Anyone in the UK hooked up to Virgin (Formerly NTL).
If your pc is running slow (ie the drive light is always on/flashing even when no programs are running.
The RPS.EXE feature part of the antivirus PCGUARD sofware could be at fault.
The cure;
Close all open windows (print out this post first though), shutdown PCguard.
If after a few seconds the HD light stops flickering and goes out then continue;
Click on the Reset All Settings button and select OK for any warnings, then when prompted restart the PCguard.
I think this might be a fairly common problem as there seems to be a lot of talk about this on the net, I have suffered from it for a couple of weeks, it persisted even after a total rebuild of the PC, this problem was eating 90% of the processors time for about 45 minutes every hour.