Slow computer - High % CPU and Kernel times

I'm a newby and Hi everyone. My oldish XP computer has just run slow. Checking Task Manager I find with no programs running, there is erratic but high cpu usage, seemingly pushed up by the Red (Kernel times) bar. (Lots of red and very little Green) I cannot determine what is causing the kernel to be so busy. How can I check this out?. I have checked for malware, virus etc. and all is clear. Starting in Safe mode, the readings are normal - i.e. with no programs started apart from the ones normally started up it shows low cpu usage I can give more details if they are needed but am trying to keep it simple. As if . . . . .

 

Computer running slow

It has taken me a long time to sort out the problem but taking advice and removing programs etc. I found that all was back to normal after I removed my new D-Link Voip Phone adapter DPH-50U. I still cannot work out just what was wrong with it and will try soon to reinstall it - but difficult to get technical help from them.