Gateway Desktop still tring to boot vista

get to the system recovery console..... and play with the bootrec commands.....
type bootrec in cmd prompt to get a list of the diff commands.... make sure your system is on the list.... and do a fix ... i did the exact same thing you did and mine is now working... thank god... i saw you ended up doing something else, but in case someone else out there is in this situation.... i wanna give gateway a big slap in the face for this inconvenience.

moreinfo:
Fixing "BOOTMGR is missing" Error While Trying to Boot Windows Vista - How-To Geek

Bootrec commands are automated in Win7 Startup Repair. THere may be other tests needed as well.

Sometimes when no WIn7 installation shows to repair after booting into Repair utility, bootrec /fixboot can force it to show.