Can Not boot into Vista

I am running Vista Home Premium 64 bit. I am also running Win 7. Dual
Booting.
Everything was fine.I was in Vista and installed Cpuid,a file for showing
temp,memory,etc on the PC.I restarted and wanted to go into Vista.The screen
comes up and Win & is default.I scrolled to Vista and hit enter.
On the screed this came up:\
Windows failed tostart. A recent Hardware or Software change might be the
case to fix:

1. Insert windows disk & restart

2.Choose your Language and click start

3. Click Repair your PC.

File\windows\system\32\wid load.exe.
If I choose to load Vista I ghet:
The selected entry could not be loaded,because the application is missing or
corrupt.

I can boot into Win 7 with no problem.

My question is if put in the Vista CD and choose repair.Will I loose any
files or programs??

I the Boot Manager is in C: where Vista is runing from.Win 7 is another
Disk,but as far as I know the boot manager for 7 is also in DriveC:??

I belive there is a way threw run/Cmd , or somehow adding Vista back to the
Boot manager.

Thank You in Advance

Doug