Hi,
It would be a good idea to run the System File Checker Tool to see if you have corrupt files
"How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7"
http://support.microsoft.com/kb/929833
Use the System File Checker tool (SFC.exe) to determine which file is causing the issue, and then replace the file. To do this, follow these steps:
- Open an elevated command prompt. To do this, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
- Type the following command, and then press ENTER:
sfc /scannow
The sfc /scannow command scans all protected system files and replaces incorrect versions with correct Microsoft versions.
If SFC finds serious faults, you may have to do a Repair Upgrade Installation, or full reinstall if you do not have a Microsoft Vista DVD.
If you can borrow a Microsoft Vista DVD you save doing a full reinstall:
"How To Perform a Repair Installation For Vista"
http://www.vistax64.com/tutorials/88236-repair-install-vista.html