How to determine version of app

Hello

I am writing an install shield for my application. I have a
requirement where I should not continue installation if the
version of a standard windows application (like for instance
MS Windows Messenger) is below a specified version.

So how do I find the versions of the installed standard
windows applications? What key in the registry should I be
looking at?
Are there any other ways of performing this check?

Any pointers in this area will be appreciated.

regards
Venky

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| Venkatesh Varadan : Specialist, D & D |
| Networking & Communications Group |
| Company : Tata Elxsi Ltd., Bangalore |
| Phone : +91-80-8410222 Fax : +91-80-8410219 |
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