My harddisk have begun acting really weird. It sometimes (quite often actually) starts working constantly. When that happens everything i run from that harddisk lags big time. When I refresh in My Computer I can see the free disk space value going up and down. It seems as XP (or something else) is creating file(s) just to delete it afterwards. I've jusat virus-scanned my computer and found no infected files. I've also disabled System Restore just in case. Anybody have any suggestions on what is causing this and eventually what will solve it???

You might have SpyWare on your computer... Have you checked it for spyware? I would recommend downloading SpyBot Search & Destroy or Ad-Aware. These are both free programs and they offer many good features like locking your host file so your browser won't get hijacked and locking your homepage so sites can't change it. When you download the programs make sure you download them and not run them from location.... Download the program, install it, update it and run it... SpyBot S&D searches and immunizes your computer for over 10000 different types of spyware, dialers, etc. If this don't work, visit my website for further assistance and tips.

I forgot to ask. Have you checked how many programs are running in the background? I got a nice little tool to help monitor Startup and Running Processes and it allows you to safely delete Registry run- commands. Programs also put entries in your registry to run at startup... If my first suggestion doesn't work then download this program and see what is running. ~~~~~~~~~~~~~~~~~~~ Starter this program is less than 800K

Other possible culprits include virus scanners set to automtically scan your disk, and the file indexer, which can be a real disk-usage hog.