Office Shortcuts Not Working

I am having a problem with my office file shortcuts not working. The ones on the program menu work fine but if I access the file through windows explorer, nothing happens and explorer stops running.
If I open the program and then open the file it works fine. It does this for all the office programs but all the non-office shortcuts work fine.
It is also a problem if I receive an office document as an email attachment. It freezes if I try to open it within the email program. I have to save it and then open it.

I have checked that the relevant file extensions are set correctly in Windows Explorer and have also checked that the paths to the office programs are working...

I know it is not a major problem - it is the annoyance factor

Any help would be appreciated