Dear all, Firstly, wow you have a wonderful forum here, seems nice, anyway I'll get straight down to my problem. I have a Windows Vista machine, a custom modified/built machine, I am not sure if it is a hardware error or compatability error but I can't find anything to say it isn't, It is a upgraded Dell Dimensions C521, Dual core 64bit 3.5ghz, 4gig of Crucial Ram, upgraded ATI HD4550 GFX card, everything else is pretty standard, generic Dell DVD/CD drive, 600w psu, thats my pc history, now for the background and the problems. I lost my Win Vista Disks and needed to reformat so I spent £70 on a copy of Win7, thought why the hell not, looks good and it's been good when I used it, I pop the disk in, boot up, go to install and select custom install, format the drive I want to install too, install, it installs fine, restarts and goes to the logo screen and gives a message saying updating the registry, the screen go blank and then it restarts again, goes to the loading screen and says "windows is starting" screen goes blank, I can move the cursor but that is it, now if i try it in safe mode it goes but says "windows is starting for the first time" or something like that, then i get an error message about it not being able to be installed in safemode and restarts. This happens with both a 32bit install and 64bit install I do not believe I can give much more information but any help would be appreciated. ps I did spend 4 hours on the phone to Microsoft Tech support, installing 64bit OS 4 times and 32bit 3 times before they gave up.