Hello to everyone. As you can see, this is my first post here even if I knew about this forum for quite some time (and read some topics of course). I had a problem for quite some time but first, here are my system specs : Manufacturer : MSI Intel Pentium 4 CPU 3.06Ghz (Intel 945P) ATI Radeon X1600 (256Mb) 1 Gb of RAM (DDR2 SDRAM, 266Mhz) Maxtor 6V200E0 (200Gb of space) Operating System : Windows XP Professional with Service Pack 2 Now, here are the details of the problem I am having : Well, this problem didn't appeared recently. We (my father and I) didn't buy and entire PC. Instead, we bought the parts and put them in the same case. I mainly uses PCs for gaming and that was the PC of my dreams... But as soon as I started using it, I realised that it was "unstable". In fact, it was restarting randomly. Often, when I turned my PC on, it could restarts itself only 2 mins after the startup and, a occasionally, one or two hours after. Then, when it starts Windows again, it could either restarts itself again after some mins or "stablize" itself. When it stops restarting and has therfore "stabilized" itself, I haven't noticed any problems while running games or running other applications like listening to music, surfing on the web, etc... My main problem is that it takes some time to "stabilize" itself : the most restarts that my PC has done before stabilizing itself was of 6 restarts ! Little precision : When it starts, sometimes I get the message from Windows XP asking me if I wanted to Send or not an error report. Additional Information : Just after buying the parts for the PC and when I realized that it was unstable, I changed from an Nvidia graphic card, to an ATI Radeon (the one mentioned above). The problems didn't stop. I formated my hard drive but it hasn't resolved the problem. Well, that's my story. I really don't know what to do or what is causing this problem. So, here I am, asking for your kind help. Thank you.