System freezing intermittently , getting desperate

Hi All,

I'm looking for some advice on what to do with this problem.

Description: On random moments my system freezes up. The HDD light stays out and processor usage drops to 0% . My mouse still moves but every program window turns greyish and does not respond. After a minute or so the system resumes and executes all the input that I gave (aka clicking on a tab, displaying the window switcher after alt+tab etc.. )

One of the problems is that I can't simulate the problem. It comes up randomly. The only thing that I did notice, is that it did never happend when I was playing a game.

Additional info: 3 Months ago a waterpipe in my room broke. As a result the device got whet. I had to replace the keyboard but apart from that everything worked fine upto now. This is also the reason that I cannot send the device back to Dell.



Solutions tried:

- 12 Format C's , even after a clean install the problem started immediatly when I opened the file explorer in windows
- Changed HDD: I used HDtune to take a look at how my hard drive was doing, since it gave a few errors I tried buying a new hdd (WD 7200 rmp SATA). I thought this was the solution but today after installing windows the problem started again.

System
Dell Studio XPS 1647 Laptop
Intel Core i5 Processor 520M(2.40GHz,3MB cache)
Motherboard upgraded to latest BIOS version
Integrated 1GB ATI Radeon HD 565v graphics
Operating System : Windows 7 Home Premium (64 BIT)


Thanks in advance