Sorry, I have been re-organizing my office and computers so it was a bit crazy plus I had no connection the whole day. I am just settling in so bare with me.

To start with, it is normal for Windows to give you that warning when you try to remove (uninstall) Windows Installer but since you will be re-installing it, those programs that were listed to not work, would be alright but here is my dilemma, how did you come to conclusion that Windows Installer was the problem, I somehow missed that part and I do not remember suggesting the removal of Windows Installer?
I thought the main problem was that you couldn't play flash videos because IE would state Flash was not installed even though it already was and I mentioned that it was more than likely caused by one of the system updates and workaround would be to use Mozilla Firefox.

So, at this point, before going any further, clarify what the exact problem is. If it was indeed the Flash issue, then you shouldn't do any of the things you attempt to, more importantly re-installing Windows Installer will not resolve the issue!