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So I installed Ubuntu 12.04 alongside Windows XP, and I played with it for a like an hour. When I wanted to go back to Windows, I chose the Windows option in the GRUB screen. It just gives a black screen and goes back to grub. I tried boot-repair as I've seen in some other post that it could resolve the problem, but it's all the same. Nothing changed. I can use Ubuntu but not Windows. Can someone please tell me how I can solve this? Thanks.