Archive for ‘Computer and Internet’

March 8, 2014

Hype HY-525-BT Mini Bluetooth Speaker User Manual Scan

This is a pretty impressive little BT speaker. I cannot find the user manual online, so put a scan here for future reference (actually from my phone, but still legible). Total 4 pages.





January 19, 2014

Share Folders Between Windows Host and Ubuntu Gest OS in VirtualBox

To share a folder and its files between a host OS (in this example, Windows) and a guest OS (Ubuntu here), there are a few steps.

Prerequisite: VirtualBox Guest Additions. The Guest Additions is necessary for shared folders to work between the host and the guest. Follow the instructions here to install the Guest Additions.

Now move to share folders between the host and guest.

From Host Side: Specify what to share

Before you run the guest OS in VirtualBox running in host OS, assign the shared folders to the guest virtual machine.


In the example above, a host folder C:\pub\code\gtest-1.7.0 is shared to the guest virtual machine ubuntu-12.10-amd64-fresh, appearing as folder name (share name) gtest-1.7.0.

From Guest Side: Access the share

After the guest Ubuntu boots, the share is available. You can verify that by checking /media:


The shared folder automatically appears as /media/sf_gtest-1.7.0. This directory is however not useful directly, because only root can access it. You have to mount gtest-1.7.0 somewhere else, for example:


In this example, I created a new directory /mnt/share/gtest-1.7.0 as the mounting point for the shared folder gtest-1.7.0. I then mount the shared folder there. The ls command confirms that the files sub-directories appear in the newly mounted folder.

Now the host Windows OS and guest Ubuntu OS will be able to exchange files seamlessly by accessing C:\pub\code\gtest-1.7.0 and /mnt/share/gtest-1.7.0 respectively.

Mount At Boot

If the guest OS is supposed to access the shared folder whenever it boots, add the mount command to /etc/init.d/rc.local in Ubuntu. rc.local runs near the end of boot process, so you do not have to type the command after every boot. I just add the mount to the end of rc.local. The rc.local file looks like this:


Because rc.local runs as root, no sudo is needed in the mount line.

January 18, 2014

Install Guest Additions for VirtualBox 4.3.6

The Guest Additions is necessary for the guest OS to interact better with the host OS, in which VirtualBox runs. For example, to share file folders or clipboard between the guest and host, and to make the guest OS desktop to fill the VirtualBox container window, you have to install Guest Additions.

Installing the Guest Additions requires making changes in both VirtualBox and the guest OS. For an earlier short summary of installing Guest Additions, see an earlier post.

Below is the summary for VirtualBox 4.3.6 on Windows 7 with guest Ubuntu 12.10-i386.

  • Host: Download the matching Extension Pack for VirtualBox 4.3.6:
  • Host: Open the Extension Pack with VirtualBox. If the file extension is not associated with VirtualBox, double click it and choose “Select a program from a list of installed programs”, then manually find VirtualBox to open it. VirtualBox will take and install it.
  • Host: In VirtualBox, choose the guest virtual machine, from Storage, make sure there is an empty IDE CD/DVD drive. The Guest Additions iso will be mounted on the drive so the guest OS will be able to run an installer from there.
  • Host: In VirtualBox, run the guest virtual machine.
  • Guest: Install DKMS (Dynamic Kernel Module Support). The guest OS will install the Guest Additions as dynamic kernel modules and so requires this. Open a Terminal window, then run:
  •    sudo apt-get install dkms
  • Guest: From the VirtualBox container window of the guest, choose menu Devices | Install Guest Additions CD image…, confirm your choice, enter root password when prompted, and run the script. Make sure there’s no errors.
  • Guest: Restart your guest OS.

After restarting, you should see the guest OS desktop automatically filling the whole interior of the VirtualBox container window. This means the Guest Additions has been successfully installed in the guest OS. You can now copy & paste text between the guest OS and host OS. You can now share folders and files between them, and do a lot more.

October 20, 2013

Windows 7 64-bit on Dell XPS 400

Dell XPS 400 is a desktop PC released in 2005, and Dell officially only supports for it Windows XP (32-bit and x64), and Windows Vista 32-bit.

I installed Windows 7 64-bit anyway on it, and it is able to detect and install most of the devices, including display adaptor RADEON X600, in the old PC. The only exceptions are the Ethernet LAN card and Wi-Fi card. Windows 7 x64 complains it could not find the driver for the network device.

According to the Dell support website for XPS 400/Dimension 9150, if you expand “Network (2)”, you would see in the list

  • Dell Wireless 1450 (802.11a/b/g) USB 2.0 Adaptor (only has Windows XP drivers)
  • Intel PRO/1000 Network Connections (has Windows XP and Windows Vista 32-bit drivers)

Unfortunately, you cannot find Windows 7 64-bit drivers there for them. However, the exact names of the device provide important hint about finding the correct drivers.

Obviously, the LAN adaptor is Intel PRO/1000. Searching the device with “Windows 7 64-bit driver” leads to Intel’s network adaptor driver package for Windows 7 From there, you can download PROWinx64.exe, which installs base drivers for all Intel PRO series network adaptors, as well as some Intel utilities. I just installed it, and viola I have internet connection. The device appears as “Intel® PRO/1000 PL Network Connection” in Device Manager.

Better yet, after gaining access to the Internet, Windows 7 64-bit found the Dell Wireless 1450 as “Ralink RT61 Turbo Wireless LAN Card”, and automatically installed driver for it. I just enabled the Wireless Network Connection, and it connects to my home Wi-Fi. Now I can put the PC wherever I want!

Manually install the Wi-Fi driver

If one has to manually install Dell Wireless 1450 driver in Windows 7 x64:

Approach 1

Follow this post: The idea is:

  • Install the Dell Wireless 1450 USB2.0 Adaptor Windows XP x64 driver
  • The driver would work in Windows 7 64-bit.
  • The utility program may not work in Windows 7 64-bit. Manually delete “Wireless USB 2.0 WLAN Card Utility” from All Programs | Startup folder, and launch msconfig and uncheck “USB 2.0 Wireless LAN” from Startup tab.
  • Use Windows to configure the wireless device.

I did not try this.

Approach 2

Directly googling for Ralink RT61 Turbo Wireless LAN Card’s Windows 7 64-bit driver was not very successful. It would get to MediaTek’s Downloads site, but you cannot find RT61 there. Initially, I got from Softpedia this driver. This did not work because Windows 7 x64 would not take it (extracting netr61.inf from cab, and it shows NTx86.6.1, which is for 32-bit Windows 7). Then I tried the Windows 7 x64 driver (netr6164.inf does show NTAMD64.6.1 for x64), and it worked. Because the INF file reveals the chipsets are RT2561 & RT2661, this implies that “PCI/mPCI/CB (RT256x/RT266x)” at MediaTek’s Downloads site should also work, although I did not try.

In short, use Softpedia’s Ralink RT61 Turbo WLAN Adapter Driver for Windows 7 x64/Windows 8 x64.

August 6, 2013

Installing Brother HL-2170W As Wired Network Printer

Brother HL-2170W is a pretty respectable laser printer that supports connections through USB, wired Ethernet, or Wi-Fi. In a previous post, I summarized how to set it up as a wireless printer. However, I have been trying different routers with various Wi-Fi settings, and each time I had to reset HL-2170W and re-install it, and it is really inconvenient. Since the printer sits near the switch anyway, I decided to configure it as a wired network printer instead of a wireless one, such that changing routers would not require me to re-configure the printer.


  1. Reset the printer to return to factory settings (if it was set up as a wireless printer).
  2. Turn on the printer, and use a Ethernet cable to connect it to your network. It should automatically get an IP from your DHCP server, typically your home router. On the router, you can see it as an attached device with name appearing like BRNxxxxxxxxxxxxx.

Driver Installation:

  1. Download HL-2170W Full Driver & Software Package at Brother Solutions Center.
  2. Run it and choose Standard Installation.
  3. At Selection Connection page, choose Brother Peer-to-Peer Network Printer (Print directly to the printer over the network).
  4. At Select Printer page, if you know the exact printer name from your router, you can choose Specify your machine by name (Advanced Users), then enter Node Name, i.e., BRNxxxxxxxxxxxxx. Click Next will install the driver.
  5. Alternatively, if you do not know the exact printer name, choose Search the network for devices and choose from a list of discovered devices. The installer will find the printer with its Node Name (BRNxxxxxxxxxxxxx) and Node IP address. Choose that printer, and be sure to check LPR Set by Node Name. Click Next will install the driver.
  6. Reboot your PC.

As long as the routers support DHCP, the printer will be accessible to the PCs on the home network through its Node Name.

July 27, 2013

No Sound When Google Chrome Playing Video on Windows 8

I got a new x64 Windows 8 box. Because I use Google Chrome most, I installed Google Chrome (32-bit) in Windows 8. There is no 64-bit Google Chrome on Windows 8 at the time. Soon I noticed that Google Chrome played YouTube without sound. I verified other programs playing sound fine, and IE plays the same YouTube video with sound. And in Chrome, after installing Windows Media Player plugin, it played some online MP3 music well. It seems that it’s problematic with Flash Player plugin.

As suggested by How to fix no sound in Chrome for YouTube, one should disable all other Adobe Flash Player plug-ins, but leave only Shockwave Flash (NPSWF32_*.dll) enabled. I checked my Chrome plugins (chrome://plugins), and found there was no NPSWF32_*.dll as Flash Player plugin. The only Flash Player plugin was pepflashplayer.dll, which is Chrome’s integrated Flash Player plugin.

However, Chrome’s the Adobe Flash Player plugin Help page lists NPSWF32_*.dll as a System plugin. So I just went to Adobe Flash Player download page to download the system plugin. The download page says that Chrome already has this plugin built in, but it still allows you to download a system plugin. I just downloaded and installed the Flash Player system plugin. After restarting Chrome, I can now see both pepflashplayer.dll and NPSWF32_*.dll as two plugins. Now I just disable pepflashplayer.dll, and enable NPSWF32_*.dll.

After restarting Chrome, it plays most Youku videos with sound. It plays some YouTube videos okay (such as this one), but not some others (such as this one). This is only a partial success.

The Google Search app installed from Windows Store does not have this problem, when it plays YouTube videos.

Edit 10/28/2013: As Sahil Jain pointed out, you need to click the speaker icon on system tray, then click "Mixer" to show the Volume Mixer. When there is a YouTube tab in Google Chrome, the system volume mixer look like this:


Obviously, Windows 8 allows per-application volume control (see Chrome and Live Mail above). If the Google Chrome volume level is 0, obviously playing YouTube is silent.

Edit 11/10/2013: I upgraded from Windows 8 to Windows 8.1, and when I launched Chrome and got a YouTube tab, I could not see the Google Chrome per-application volume control in the system volume mixer, and there was again no sound in Chrome! Restarting the PC did not work. Finally, I had to go to chrome://plugins, and noticed both pepflashplayer.dll and NPSWF32_11_8_800_94.dll were enabled under Adobe Flasher Player (2files). After I disabled pepflashplayer.dll, and left NPSWF32_11_8_800_94.dll as the only enabled Adobe Flash Player plugin, the Google Chrome per-application volume control appears in the system volume mixer.

Conclusion: Disable all Adobe Flash Player plugin files but NPSWF32_*.dll, then check the volume mixer per-application control.

July 2, 2013

Quick Feature Comparison Chart for Intel Core i3, i5, i7 CPUs

CPU Cores Turbo Boost Cache Size Hyper Threading
i3 Dual-core (2) N/A 3MB Yes (4 logical cores)
i5 Quad-core (4)
   except i5-661 (2)
Yes 6MB No (4 logical cores)
  except i5-661 (4 logical cores)
i7 Quad-core (4) Yes 8MB Yes (8 logical cores)

Reference: What’s the difference between an Intel Core i3, i5 and i7?

June 23, 2013

Definitive Guide: Factory Reset Brother HL-2170W Wireless Printer

The little printer was easy to set up initially, see a previous post. However, Brother does not have very good configuration support if anything changes in the wireless network, for example, your wireless router, SSID or key. Supposedly you just need to re-connect the Ethernet cable, and re-run Wireless Setup Wizard for Windows to let the printer know your new wireless network information, and restore printing. What you may often see, however, is that the Wizard reports it could not find the printer at all, letting alone allowing you to change its configuration.

The problem is that the printer is stuck with the stale network information and even prevents configuration connections. Whenever the PC cannot see the printer, the recommended approach is to factory reset the printer and redo the setup process. You can find the official factory reset instructions here. However, the instructions are too concise and does not tell you what is normal and what is not during the process, and you could wonder if you did it right. I stumbled a few times on that. By combining the official instructions with Brother HL-2170W: Installation Gotchas + Reset to Factory Settings and How do I configure the wireless printer with the temporary use of a network cable and install the printer driver in Windows, and after some experiments, I believe below is the best guide available over the internet for factory resetting Brother HL-2170W:

  1. Turn off the printer.
  2. Remove the Ethernet cable and USB cable from the printer.
  3. Remove paper from printer and close the front cover. Removing paper is optional and to save paper and toner; if you go wrong, the printer may print TEST PRINT pages, which I have had a bunch…
  4. Hold the Go button and turn on the printer. In fact the Go button is the only button that you can operate. It is white, and has blue light when on.
  5. Keep the Go button pressed down until the Toner, Drum and Error LEDs light up. For my printer, as soon as I power up the printer all the three LEDs light on immediately.
  6. Release the Go button and make sure the Toner, Drum and Error LEDs go off. Again, for my printer, the three LEDs go off right after I release the Go button. At this time, all the LEDs and the Go button light are off.
  7. Press (and of course release) the Go button 7 times. When the Go button is pressed, its blue light is on. After 7 presses, all the LEDs and the Go button light are off. For a few seconds, the printer may not seem to respond to your presses at all. Don’t worry, I believe it is just unsure and waiting for you to press more if you want to do some other secret settings. For example, pressing Go more times can print the TEST PRINT page.
  8. After the waiting period (for my printer this silence takes about 10 seconds), all the Toner, Drum and Error LEDs and the Go button light come on briefly and go off, then the Go button light slowly flashes for a few times. This means the factory reset is successful.
  9. After the factory reset, as you usually see when the printer is turned on, it makes some noise and then the Go button remain lit. The printer is now ready.

If you believe you go wrong in the middle, just turn off the printer and start over. The procedure above could be too much for first time users. In my point of view, since any change in network settings essentially requires resetting the wireless printer, Brother could have really added a reset button in the back of the printer and made it painless.

Once your printer is reset, you can use an Ethernet cable to connect it to your home network. If your router has a DHCP server, HL-2170W will try to get an IP there. The instructions say that you may need to wait for 1 minute, but I can see that the printer gets an IP right away from my router in the router’s management page. It is also shown that the printer names itself as BRNxxxxxxxxxxxxxx in the DHCP client list.

Now you just need to run Wireless Setup Wizard for Windows, and it will see the printer with the BRNxxxxxxxxxxxxxx host name and IP from DHCP. You just need to follow the rest of Installing Brother HL-2170W Wireless Laser Printer to finish the installation.

May 17, 2013

Windows XP: Cannot Delete a Randomly Named Folder or File: Access Is Denied

Below is a screenshot of the problem: You cannot delete a folder or file because of “Access is denied”, even when you logged in as administrator, and the subject seems definitely rubbish (well, you believe, this may not be true, for example, it might be in the process of installing Windows updates and patches).


It is generally easy by taking over the ownership with administrator credentials and then delete it (see Delete randomly named remnant directories from installers).

Sometimes, the folder or file is more adamant from deletion. You cannot find the Security tab in the Properties page of the file or folder. On Windows XP, this is because Simple File Sharing is turned on.

  • Windows XP Professional: Simple File Sharing is turned on if the computer does not join a domain (i.e., joins a workgroup)
  • Windows XP Home: Simple File Sharing is always on (unless booted in Safe mode)

So the solution is:

  • Windows XP Professional: Turn it off from Folder Options | View | Advanced settings, see here
  • Windows XP Home: Boot into Safe mode (pressing F8 before Windows launches), then turn off Simple File Sharing. You also need to change the permissions in the same session, because when it boots into Normal mode, Simple File Sharing is turned on again, and you lose the Security tab.
  • Windows XP Home: Boot into Safe mode (pressing F8 before Windows launches) as Administrator, then right-click the folder in Windows Explorer, choose the Security tab (only available in Safe mode), Allow Permissions for Administrators for Full Control, choose Apply. Then delete the folder.
April 12, 2013

LinkedIn People You May Know

Today I happened to see People You May Know at LinkedIn, and side by side I noticed this:


Not sure about the Chinese names, but this was quite a coincidence!


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