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My Windows 7 got infected with a seriouly bad virus, just because I disabled my anti-virus, so after I re-enabled it I tryed to fight of viruses by doing a start-up scan, but my anti-virus froze and got disabled by the viruse, and all system files also got infected. So I re-installed Windows 7 and now I don't see the Ubuntu boot loader and I don't know what to do. I don't want to have to re-install Ubuntu too.
I'm new to linux, I don't even know what grub is.