You can reinstall using another Vista disc. Either borrow one or get one from ebay.
Installing it is easy - the only slightly tricky aspect is getting the correct drivers for the laptop. Windows will have its own for many of the items, but you may have to do a bit of searching for things like the built-in camera (if it has one). Manufacturers websites can usually help. Once the laptop is running again and has internet access, a program like SIW will help determine what hardware is installed.