I am having an issue with MP 11. I also have 10, and kept it as some users in my company still use 10, so I create maps for them using 10 so they can open them.

Anyway, I created a map in 11, and when I went to open it, it wouldn't open. It lists it as a 2010 file, but will not let me open with 2010 as it says its created with the newer version.

Also, when I click open with, 2011 is not listed, and when i click browse to open with 11, I click the .exe, but it still defaults to 2010 and i cant open with 11. The only way to open it is to open 11, then do a file-open.

Also, I checked back to other maps I had created with 11, and I am having the same issue.

Any help would be appreciated.

thanks in advance

That might be solved using the ol'
"C:\Program Files (x86)\Microsoft MapPoint 2011\MapPoint.exe" /regserver in the Run dialog box.