Light room 4.1: Export warning started appearing after installing Microsoft Office

Hello friends,
I am using windows 7 64 bit on my PC with 6 GB ram. I have been using adobe photoshop lightroom 4.1 on my machine, and it was running perfectly but just yesterday I started facing an error after I installed the Microsoft office 2010 home student edition.
After its installation, when I try to export a photo, the photo is exported correctly but the following error pops up on my screen every time even if Microsoft office is not running. I have attached the screenshot of the error below:

The error says:
Unable to Export:
An internal error has occurred: Win32 API error 2 (“The system cannot find the file specified.”) when calling ShellExecuteExW from AgWorkspace.shellExecute
Can anyone please guide me what should I do to remove the error? I'll be really thankful for any kind of help and guidance.
Waiting for your reply
Kindest regards
