I have a Gateway m305 crv and it was running windows xp and my sister upgraded it to vista and for a while now its been saying that vista isn't valid and the laptop only runs with minimal access. I cannot get to any of my files and I downloaded Ubuntu to my external hard drive and tried to install it but I keep getting the error that the drives are not ready and I have to do this in safe mode.
The first thing that I would try and do would be to log into Safe Mode into Windows and verify that you have activated the version of Windows or in this case Vista. If your sister did not have an access key after installing Vista she has 30 days to input a valid key.
This could be as simple as making sure you have an Internet connection, then search for Activate Windows and as long as every thing is good (product key, etc.) you will have full functioning Windows. However, my recommendation would be to burn an ISO of Ubuntu on a CD (Live CD), boot off the Live CD and drop Vista. I made the switch 4 months ago and I love every minute of it!