A If a USB item is not being recognised properly, try using 'USBDeview' (freeware download from http//www.nirsoft.net/utils/usb_devices_view.html) to 'uninstall' it. Then, when you restart the computer, with luck it will now be recognised as 'found new hardware' and will be reinstalled.

After this, run the 'HP drive key boot utility' (http//bit.ly/oI9Pg) or http//www.apacer.com/en/support/downloads/Repair_v2.9.1.1.zip to reformat as well, to get the full memory back.

If neither works, as a final attempt, try HP's Flash drive utility which you can download from http//files.extremeoverclocking.com/file.php?f=197.

If it still doesn't work, then it looks like the hardware is faulty and will need to be replaced.

Q I'm using WindowsXP with Avira anitvirus. My problem is that my system somehow got infected with virus which is making exe. files of the same name as the folders that exist in my external HDD. If I delete these exe. files from command prompt, then my folders also become invisible (not hidden). The same thing happens when I create a new folder. I cannot format my external HDD since I have a lot of important data on the system. Please suggest ways to solve this problem. Also, suggest an effective antivirus.

A You can download a removal tool from http//tec-updates.blogspot.com/2007/10/new-folderexe-virus-removal-tool.html which you should run in Safe Mode.

You can also manually remove it for which you will need to delete the file named svichossst.exe in System32 folder of your windows directory.

Go to Start > Run > type regedit and press OK

Now go to [HKEY_CURRENT_USER SoftwareMicrosoft...
'@'= [HKEY_CURRENT_USERSoftware Micros...
'Yahoo Messenger'=[HKEY_LOCAL_MACHINESOFTWAREMicrosoft...NTCurrentVersionWinlogon]'Shell'= 'Explorer.exe'.

After following any of the above instructions, just download the file from the following link and install it.

http//www.symantec.com/security_response/writeup.jsp?docid=2004-050614-0532-99

You will find here a link named, UnHookExec.inf at the bottom of the page. Just download it and then right-click on it and click on install.

Hope this helps.

Q How can I use the wireless Lan of my laptop (Toshiba Satellite A70) as a Bluetooth? Please suggest free software.

A The short and quick answer is, you cannot. This is mainly because they are very different technologies even though they both operate on the 2.4 GHz band. Wireless Lan technologies were originally designed to complement the existing fixed-connection Lans made up of wires, fibre optics etc. The IEEE 802.11 standard (as it's technically known) is better suited for wireless local area networks. It is faster and gives wider range of use.

Once connected the user can surf the net, send and receive email, typically the same applications the user would attempt on a wired Lan. However, this all comes at a price battery power. Due to 802.11bs power demand to sustain high throughput and medium range, only certain portable devices like netbooks, pads, PCs, laptops can supply this power for long and still retain a reasonable battery life. Handhelds, mobiles etc., are not so lucky; they dont possess the energy to allow 802.11b to operate for long periods without directly impacting on their own performance. The price of the chipsets is also a factor. To combat these Wpan, technology such as Bluetooth is required.

Bluetooth on the other hand is a standard for a small, cheap, low-power radio chip to be plugged into computers, printers, mobile phones, etc. A Bluetooth chip is designed to replace cables by taking the information normally carried by the cable, and transmitting it to a receiver Bluetooth chip, which will then give the information received to the computer, phone, etc. The technology connects personal devices within a small area. The Bluetooth protocol uses FHSS (frequency-hopping spread-spectrum) transmission which means that the chip transmits and receives on 79 different hop frequencies from 2402 to 2480 MHz, switching between one hop frequency to another in a pseudo-random sequence, 1,600 times a second. It uses GFSK modulation and the maximum data rate is around 721kbits/s and the maximum range is meant to be 10 metres as compared to megabits of data transfer over Wlan and 300 meters average data range.

So, in summary Bluetooth technology is designed for quick, seamless short range networks, and features better power consumption, small protocol stack, robust data and voice transfer and cheap price. These same features that make it so suited for Wpan give it a disadvantage in Wlan terms, where it would be described as slow and limited. Likewise, 802.11b is designed for infrequent mobility, IP-based data transmission, medium range and high data rate make it an ideal choice for Wlan, but a poor choice for Wpan, being clumsy, expensive and power-hungry.

Q Is it true that the virus detection software, Threatfire, only terminates the virus process but does not delete it? Is this tool useful to us and can it be installed along with an antivirus?

A ThreatFire is sophisticated real-time behavioural analysis software which is able to stop what are known as 'zero-day' threats solely by detecting their malicious activity. It's highly effective as complementary to your primary antivirus software and will run in the background without causing problems.

I'd personally prefer 'PrevX', which has been my choice for many years now. Of course, you can use either that or ThreatFire for complementing your protection. Both require subscriptions to remove the virus, so you can only use them for detection. Neither will clean the virus nor offer real time protection without purchase.