I've been in a trouble last days. I have a 500gb HD with 3 partitions. The bigger one (300GB) is for persistent data (college files, music, etc). In the second I've installed an Ubuntu system I use for development. In the third one I've a Windows XP for gaming. When my PC starts the grub step up and ask me to select an OS, Ubuntu is the default option.
Now, I've decided to switch to Windows 7. I made the normal installation procedure, and worked everything all right. Now, when the PC starts it doesn't show the grub screen anymore!
I guess the Windows MBR put itself on top of the Grub.
How can I fix it without losing data, or reinstalling Ubuntu??