Go into Task Manager (ctrl-alt-del), open the Processes tab and find out what processes are using the CPU. You can sort on the 'percentage' column by clicking the header.
System idle means 'doing nothing'. Normally, it's some 99%. With you it might be 0 with other processes totalling 100%.
Post your findings.
Earlier today (or yesterday now) my laptop started to run very slowly. I just now noticed it's cpu usage is at 100%, it goes down to 80% now and then. But this is definetly not normal! Please if anyone knows why this is happening, some help on turning off processes or anything would be very nice!
Now I don't know what to do, I can say I only have 11 gigs left on my drive, but thats surely enough to run normally. I'm guessing this could be a potential virus?