Ok, it sounds silly but it does exactly that. Sometimes it restarts itself, sometimes it just freezes and sometimes it gives the BSOD. Totally randomly. It may happen few times within one hour or it may not happen for a day. Usually it happens few times a day. Here is what I have done: 1. Cleaned all the dust. 2. Tried to remove memory sticks one by one and run with just one of them. If I only have one stick it crashes less often but still does. 3. Run memtest with one memory stick. After 30 passes still no errors. 4. Upgraided from vista to windows7 ultimate. 5. Checked power supply voltage - OK. Re-checked next day - still OK. 6. Checked processor temperature with everest and speedfan. Looks OK though T goes up to 47-50 the maximum is 55 for my Athlon 64x2 5000+. Don't know what else I could do... Here I attach 5 latest minidumps and I would really appreciate any help.