Finally my laptop is back working smoothly again... Everything started more than one month ago, when I noticed that my laptop was a lot slower then what it should be, and I found out that it was a problem with too much CPU time in kernel mode: this usually means a problem with the hardware. 10 days later, I decided to spend a night backing up all my data to the external drive and reinstalling everything. Unfortunately the reinstallation didn't solve the problem, the time spent in kernel mode was still too much, and the application were still very slow. Other 10...