There is no right and wrong, the answer is subjective.
If it were me I would use Ubuntu to save my stuff and go with Seven.
I had Visa and now have Seven, I truly like it. We can save your stuff with Ubuntu.
We can then buy an upgade 7 and actaully do a clean install just like the full cost DVD.
I can get you going with what you have. I will give you a BSOD analysis and a boot DVD if needed, but at the end you have the same old Vista.
You can get an upgrade Home Premium Seven for under 150.00. If these tough times did not leave you short of cash, what a nice way to start the new year.
Others may come by and give you another scenario, but it comes out the same.
We can try to save what you have, but then you have an OS that will disappear shortly or go with Seven.
A clean install of seven with formatting will get rid of all problems even malware etc.
We will be here for whatever you decide.