1) Boot with your Vista/Windows 7 installation disk. Hit <Enter> at the language selection prompt then hit <R> for Repair to get to the Repair section.
2) Select the command prompt (console) and type in the following commands:
BootRec.exe /fixmbr
chkdsk /r
BootRec.exe /FixBoot (#updates PBR partition boot)
BootRec.exe /ScanOs
BootRec.exe /RebuildBcd
http://www.sevenforums.com/tutorials/20864-mbr-restore-windows-7-master-boot-record.html
You may have to make the C partition active in order for this to work, at this point without this script we do not know the set up, this is the additional script to be run from the live ubuntu to diagnose.
http://bootinfoscript.sourceforge.net/