why is this happening

i have done all the spyware checks, virus scans but when my computor is idle the red light on the harddirve flashes all the time. ive cheched the task manager and the cpu usage jumps between 2%-8% constantley.i even unplug the internet line and the same happens.

i am running nortons could this be the problem

 

2%-8% jump on CPU usage is really not that abnormal, also HD light being on red all the time could indicate a bad or misbehaving application/process/service/device driver activity rather than a malware infection. But if you are confident that your system performance is laggy and erratic, then find out when this behavior exactly starts to occur, if right from logging on to Windows then I'd recommend you scan your Windows startup entries and disable unneeded/suspicious ones to see if it makes a difference.
I recommend StartupControlPanel for checking the startup entries in various locations.

 

Process Explorer can usually identify odd CPU jumps better than the task manager can

 

What operating system are you using? XP is much better at managing resources than 98/ME.

What is your swap/virtual/paging file set to?

How much free space do you have and have you defragged recently?