I have a Dell Dimension 8400, with 3.5 gb RAM on a 32 bit processor with Windows XP and a 500 GB HDD. I installed Ubuntu a while ago (worst decision ever), and had it with the option to dual boot. However, as soon as I went to switch to XP one day, it only came up as a black screen, with a flashing white underscore at the top left. I was wondering what to do if I can bring it back to Windows XP or maybe even Windows 7.