QUESTION My Windows XP Home PC is running very slowly, even though I've doubled the RAM allocation to 2GB. All Microsoft updates and service packs are installed and I use Symantec Norton 360 to keep the computer clear of nasties.

I've also tried defragging the hard drive, which the analysis tool said was 22 percent fragmented. After running the defrag tool built into Windows and Norton 360's Disk Optimiser, the hard drive is still 22 percent fragmented. Chkdsk doesn't shed any light on the matter. Can you help? Roger Papworth

HELPROOM ANSWER The fragmentation report you included with your email shows some large files in your My Videos folder, one of which is 9GB and takes up almost 11 percent of your hard drive's capacity. Video can't be defragmented.

The report also shows that your page file size wasn't increased when you added the extra RAM. The page file won't usually be defragmented as it's 'in use'. Using the following steps, however, you'll be able to delete any temporary and unused files that are taking up unnecessary disk space.

Download and install our old favourite, CCleaner. Run the cleaner utility. Also delete old Windows Update files by right-clicking My Computer, then choosing Manage, Services. Right-click Automatic Updates and select Stop. Navigate to your Windows folder and delete the SoftwareDistribution folder. This folder will be recreated when your PC reboots.

If possible, transfer the contents of your My Videos folder to another machine or an external hard drive.

Turn off the page file: right-click My Computer, then click Properties, Advanced, Performance, Settings, Advanced, Virtual Memory. Select Change, followed by 'No paging file'. Click Set, ok, press ok again and reboot.

When the computer restarts, run the Windows Disk Defragmenter. You should now see a lower percentage of fragmentation, although you may need to run the utility several times. Turn the page file back on and set it to ‘System managed size' to ensure Windows is using the correct amount.

Get free tech support 24 hours a day at PC Advisor's Helproom Forum