From reading your post, it looks as if it has gone beyond what a home user can recover or repair.
Their are professional companies that may -I repeat MAY be able to help, but they are expensive.
Could you contact the 'Professional' who repaired your machine and ask if they could restore the harddrive for you?.
As you do not have a VISTA disk, He/She must have used a Vista CD. Could you ask them for a copy of the operating system they put on your harddrive, I assume you paid for the repair and they may either restore it for you at a reasonable price( as they have already have some of your money)or supply you with the disk, so you can restore it yourself.
I assume you have a licence Number (usually on the base of the machine.
If you could borrow a friends CD (or ask a friend to help)you can clear the harddrive (re-partition & re-Format) then rebuild your system using your friends CD and your own licence number.
Motto of this:
If you do not know what you are doing NEVER remove any operating system file unless you are 100% sure of what you are doing, regardless af what any search engine tells you.