Vista Laptop, OK!
Vista, mmmhh, nice.
UAC and Admin, disabling UAC often won't help, even a second account YourName just given (Admin),
you need to have full Admin (Administrator), that's a small difference in Vista, for older games this is tricky but helps.
There are Tuts in the web how to get Vista unlocked, a second thing before proceeding,
check unnecessary services, trust me, some unticked, make your day, if left,
they're slowing as hell...
UAC
real Admin in Vista
unnecessary services for LapTop in Vista
Third, never install on C:, unless you can't do another way

Try not to run via USB, if you can splice your HD or what that is called or go the
"I told you this is crap" on C:
I got IL-2 running on a Lappy this way, I was not allowed to splice (partitition) UAC disabled, full admin and on C: starting with Admin rights and compa-Mode
I think to remember you need at least to install IL-2 first in order to get it done?
If I reboot my Vista, it won't accept my Backups too, so I do start fresh and then my Backups do work.
Vista: insert the DVD, and open menu manually, not autrorun, start the installation as admin, blabla, if setupexe won't work, there's this msi,
that worked sometimes, if the other failed.
I remember to have done this in order to get the Laptop to accept IL-2 at all. Since you have Backups this is just for the Registry
I think.