As a follow-up to the question
… I used Process Explorer to check my PC.
I found that there's an average 30-40% of CPU being used by
Interrupt. Is that normal?
If it is not normal, could you suggest any method to check for the cause? EDIT: Although this question was tagged as an exact duplicate of another question, I found the solution on the other question is not working in Windows xp. Installation of Windows performance toolkit on my Windows xp machine doesn't work to make the command "xperf" working in command prompt. If it is possible, please help to provide some other method to find the cause.
I've execute the DPC Latency Checker and it suggest a broken driver. I checked in the Device Manager and everything seems fine. No Yellow "!" symbol.