To transfer Windows Vista to another hard drive, perhaps when fitting a larger one in your PC is not easy. This is because, effectively, a bespoke version of Vista is created when the software is installed
You cannot transfer the operating system by just copying the files, you need to clone the entire disk. There are various utilities available for this, one of the best known is Acronis True Image. You will need to buy this (or borrow it) but it works faultlessly and the cloned hard disk is instantly bootable, nothing else needs to be done. You can also use it to perform incremental and full image backups as well as cloning disks. You can download it here: http://eu.acronis.com/homecomputing/products/trueimage/ copy. There are other disk cloning utilities, some may even be in the public domain, but they may not have the same functionality.