side by side configuration is driving me mad!

ok, so for a while now ive been getting errors which appear to be when i try opening microsoft office , and windows live programs.
For office, when i try to open a file from computer, or open the program itself, it comes up with this: "this application has failed to start because its side-by-side configuration is incorrect. Please see the application event log for more details".
This is what it says in the event log: "Activation context generation failed for "C:\Program Files\Microsoft Office\Office14\EXCEL.EXE.Manifest". Dependent Assembly Microsoft.VC90.CRT,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.30729.1" could not be found. Please use sxstrace.exe for detailed diagnosis."

Now when i try to open a windows live program such as windows live messenger, i get the same side by side error message, and the event log brings up this: "Activation context generation failed for "C:\Program Files\Windows Live\Messenger\msnmsgr.exe". Dependent Assembly Microsoft.VC90.CRT,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.30729.1" could not be found. Please use sxstrace.exe for detailed diagnosis."

Please if anyone could help, i would really appreciate it. ive tried system restore, defragmenting, re-installing the programs, registry cleaner, and still, the problem hasnt fixed.

many thanks in advance

Take a look at this- Prevent "The application has failed to start because its side-by-side configuration is incorrect..." error starting Access Just substitute Excel for Access. I recommend you export your registry with a name and location you can remember before doing the registry edits, if you choose to try it.