More details about why I am interested:
I tried to make a "release" app to run on another PC, but the app failed to start on the other PC.
It needed VC90.CRT, which I installed using redist_x86.exe (or similar, dont' remember the name now).
It still would not start, it needed VC90.DebugCRT, which is not redistributable according to Microsoft.
This is why I suspect I have inconsistent debug/release app configuration, maybe linked to debug libraries when it should be release libraries.