I recently installed norton software, updated the software and everything ran fine until later yesterday, Vista got slow for some reason, if I clicked computer, it would take a long time to pop up, also the same application, everything took a very long time to start suddenly. Every new application/window took 5 minutes or longer to pop up, even the quick launch menu took a few minutes to pop up after i clicked it with the mouse, very,very annoying. It took a very looong time to start the reliability and performance in computer management. There I discovered that cpu activity was most of the time at 0% also the disk activity was m ost of the time 0%, but once in 30 seconds or so there was cpu and disk activity and than went to 0% again, as an on/off switch. I restarted and it was only getting worse, did a check disk, which did not help much. Once I was in windows again , I checked the system restore and for some reason all my previous restore points were removed. I removed norton internet security, since that was the last software I had installed. But after a restart it was still not back to normal, everything was still very slow. Then I booted into XP x64 which would start normal, I checked both disks with HD tune. One hd(seagate 250 sataII) had 0.6% damaged blocks(also it gives a read error when I test it with HDtune), but vista is installed on another hd which contained no errors so and I was running xp now on the disk that contained the damaged blocks which could not be the problem. Also I had no vista pagefile on the 250GB disk. (But I'm going to RMA this disk with errors) I opened the case and found out by touching the SB heatsink that is was very hot, as hot as a northbridge hs which suprised me. I did a search on the internet and found that more people were talking about a hot southbridge. Well I never felt a southbridge hs as hot as a northbridge sink! After I logged of from windows xp, restarted and booting up in vista again, it seemed to run run better again minute by minute and there was again continues cpu and hd activity. And I decided to re-install norton internet security and till now it seems to run fine again. But still I don't know if it is normal that my SB heatsink is so hot Could a harddisk with a few damaged blocks cause a hot southbridge and could this be related to the sudden slow-down? I only have one 80 and one 250 GB harddisk installed and I don't use RAID. This is the result of the error scan from the 250GB disk. Can this disk cause the problems when running Vista x64? Even tho Vista and most applications are installed on another disk? Xp runs fine on the harddisk with the damaged blocks. Also did registry scans and defragged the partitions but did not find anything what could have caused that sudden slow down/non responding problem. Both disks are virus free.