Quote Originally Posted by jpn View Post
Looks like the file might be in use so it cannot be overwritten.
Yep, that was the problem and I even figured it out on my own after a well-slept night

You have an older version of Qt in PATH. Use Dependency Walker to see where it attempts to load the libraries from. A Qt application compiled with Qt 4.4 can be run against Qt 4.5, but not vice versa.
Now it gets interesting. I have no previous Qt installed on my comp. Dependency walker says that I am missing 'IESHIMS.dll", even though by fast googling I found that is should be installed on every computer. Qt paths seem correct.

I made a copy of original install of Qt, and for example Designer run from there works like a charm. But when I try to run it from folder which was compiled using MSVC, I get the previously mentioned error.

God I miss Linux as a development platform.