My system crashes (BSOD 0x0000001A) after running for some minutes/hours/days (it is very variable - but if it is left powered up it usually crashes after a day or two). Sometimes it happens while I'm actually using the computer e.g. browsing the web, but it also happens when it has been left idle. I can't be 100% certain, but I don't *think* it has happened while playing any games etc. I've been through the steps given in the thread "Before posting your minidumps, please read this.." but I don't detect any change in behaviour. In addition, I have tried swapping out RAM modules, and have installed some brand new Crucial modules in place of the Dell originals, again with no apparent change in behaviour. I did have problems with crashes during AVG antivirus scans, but have since completely removed AVG (Free version) from my system and installed Bulldog AV instead. I'm really looking for some pointers here as to where to start looking for whatever is causing my problem. The machine in question is a Dell XPS 630i, with 4GB RAM and running WIndows Vista Home Premium (32 bit). I have attached the most recent minidumps. Any help/pointers gratefully received.