Hi,
1. Have you made any changes to your computer prior to this issue?
2. What is the name of the program you’re unable to install?
3. Is this an issue installing a particular program or with all the programs?
Follow the suggestions and see if it helps.
Method 1
Run System File Checker tool.
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
Method 2
a) Click Start.
b) In the search box type cmd
c) Right click and select Run as administrator.
d) Type the following commands and press ENTER.
regsvr32 jscript.dll
regsvr32 vbscript.dll
Method 3
Check if the issue exists in a clean boot state
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
http://support.microsoft.com/kb/929135
Note : After troubleshooting follow Step 7: Reset the computer to start as usual
Also see:
How to troubleshoot script errors in Internet Explorer on Windows-based computers
http://support.microsoft.com/kb/308260
What should you do about Internet Explorer script errors?
http://windows.microsoft.com/en-US/windows7/What-should-you-do-about-Internet-Explorer-script-errors