Errors when trying to reconfigure MS BTS 2006R2.. Need immediate help Thanks!

Some files got corrupted on BizTalk Server 2006. So I am trying to reconfigure it.  

When I tried to repair it through Add/Remove programs, it gives an error message ‘The Microsoft BizTalk Server 2006.msi file is not a valid installation package for the pdt MS BTS 2006. Try to find the installation package Microsoft BizTalk Server 2006.msi in a folder from which you can install BTS 2006.msi’  Error 1706: No valid source could be found for MSBTS 2006. The installation could not continue’

When I tried to remove it through Add/Remove programs, it gives me an error ‘Error 1722. There is a problem with this Windows installer package. a program run as partof the setup did not finish as expected. Contact your support personnel or package vendor. Action LaunchConfigFramework_SlashU.C292B659_9DE5_41D2_827B_555FE3D84FF7,
location: C:\Program files\Microsoft BizTalk Server 2006\Configuration.exe, command:/u’

So I’m neither in a position to repair nor remove it (so that I can reconfigure it..)   What’s the work around in such a scenario. Thanks for all the helpful suggestions!