|There are many things you can try to attempt to get Vista working properly again witthout having to re-install it from scratch, but it's too late for that now. |
You can access files on the hard drive even if the operating system will not work properly, if the hard drive itself is not failing,
- in any case, by removing the drive and connecting it, one way or another, to another working computer with an operating system, and not attempting to boot from your drive on that computer
- if your computer is otherwise okay, by booting the computer from something with an operating system that can read Vista's NTFS partitions, such as a CD with Linux installed on it.
Installing an operating system (2000 and up) from scratch deletes the existing data contents of the partition Windows was installed on.( If you had one or more other partitions it's / their data is not deleted.)
By default deleting files does not erase the data in the files - it only erases the data about where they were located on the drive, etc. .
You will only be able to recover data that is in areas on the drive that has not been over-written with other data., The longer it takes you to first try that, the fewer files you will be able to recover. You will recover the most files by not booting from your drive at all and accessing the drive from another operating system.
You don't need to recover standard Windows files if you can install Windows again, or any data that you can easily install again. You only need to attempt to recover your personal files that can't be replaced .