Hi to all, I have been using my desktop a lot lately and decided I had to replace the stock fan on my Nvidia 8600GT as it was noisy with an Accelero S1 Rev.2. I also have a 2nd vga an Nvidia 210 which came with passive cooling. I run two vga monitors. My mobo is a Foxconn P35-Ax-S with an intel core 2-duo E6550 with stock Intel fan. My case is a Coolermaster Centurion II which has a 140mm front fan, a 120mm on the side and back. PSU (OCZ) is mounted on the bottom and is upside down - the fan is intaking from the bottom of the case and exhausting towards the back. Recently it has been quite hot here with room temperatures around 30 degrees. I have speedfan and normally this reports cpu at 34-40 and vga 1 at around 50 and vga 2 at around 40 or less. I sometimes leave my desk and find that after about 15-20 minutes the computer screen is frozen and that my 2nd monitor is on standby (led lit amber) or I find that the 2nd monitor has been "removed" from the system even in hardware devices. I have to switch off completely to restore as resetting does not being the 2nd monitor back to life. I also noticed that the cpu fan is sometimes running at full speed when this happens but according to speedfan log the cpu and vga1 (8600gt) would be around 50 degrees while the 2nd vga around 45 when the freezing of the screen occurs. I think that this is normal but somehow this freezing/2nd vga removed is happening. Am I maybe setting my mobo fan cycles wrong or am I doing something else wrong? My mobo fan settings say: Fan 1 Mode setting - Auto fan by DutyCycle Temp 1 limit of High - 85 Temp 1 limit of Sec - 70 Temp 1 limit of Thi - 60 Temp 1 limit of Low - 50 Fan 1 Highest Setting 100 Fan 1 Second Setting 80 Fan 1 Third Setting 70 Fan 1 Fourth Setting 60 Fan 1 Lowest Setting 50 My whole system is: Foxconn P35-AX-S mobo Intel Core-2-Duo E6550 2.33GHz 4GB DDR 2 ram 1TB WD hard disk Nvidia 8600GT - 1GB ram DDR2 Nvidia 210 - 512MB Coolermaster Centurion II case I would appreciate some tips on this situation as I have to put an 8 inch desk fan blowing on the side of the opened pc case to keep it from freezing etc. Thank you for any info.