It isnt a standalone program- it is part Windows- The only why it could have got "broken" is through Windows Corruption such as caused by Malware or programs like Registry cleaners.
The only way you can fix this: Back up User data before trying a reinstall operation
1. try a system restore to a point before the corruption occured.
2. Try a "upgrade" install of Vista
3. Do a repair/full re-install of Vista
OS Vista Ultimate X64 SP2 CPU T7600G Core2Duo 2.66 Ghz Motherboard Intel 945PM + ICH7 Chipset Memory 4GB DDR2 PC2-5300 667MHz Graphics Card Mobility Radeon x1900 256MB Sound Card Realtek HD Monitor(s) Displays WUXGA 17" Screen Resolution 1920X1200
Mouse Wireless Microsoft 3000 Hard Drives 640GB 7200RPM SATA/RAID 0 (2x320GB)
and 320GB 7200RPM External Internet Speed 10 mbps/2 mbps Other Info Optical Drive:
Panasonic UJ-220 DL BD-RE (Blu-Ray)