Hi, I have this phenomena, where windows XP keeps hanging during the copying files for installation phase, in the Windows Installation Dos Mode. I have attempted with XP Home SP1, and XP Professional, as well as XP Professional SP2. It hangs consistently at the same series of files. USRRTOSA.DLL and subsequent USR files always hangs the XP installation. I am baffled as to the cause of this, I've read up and it seems that its to do with a US Modem Manufacturer, so I disabled the Modem in the Bios (the modem card is removed), Removed the Gigabyte USB Extention card I installed, so the Hardware is pretty much what was on it before. The drive is not the issue, I removed it and installed successfully on another PC, CD Rom is not the problem, is there a particular cause for this?