Last two things to try now before checking that 1: your Xp installation is ok and 2: that you have not suffered a malware attack when torrents were being downloaded, the latter I cannot help you with but my colleagues on the Malware Forums are excellent and you will be in good hands if you do in fact require their assistance.
But first I suggest that you upgrade your IE7 to IE8 and uninstall Firefox and see how it goes for a while and then post back please.
IE8 download from http://windows.micro...er/downloads/ie
Having re-read the topic I noticed the option below has not been tried;
•Click Start, and then click Run. Type cleanmgr, and then click OK.
•Select the drive-letter for the current Windows installation and then click OK
•Select Temporary Internet Files from the list
•Uncheck all the other entries and click OK
•Click Yes to confirm deletion
Edited by phillpower2, 29 December 2011 - 10:54 AM.
Additional information provided.