So, after a clean format of my machine, I had this weird error in Microsoft Visual Studio 2005: it wouldn't compile one of my web projects. Compilation failed with the following error:
(O): Build (web): Unable to find the required module. (Exception from HRESULT: 0x8007007E)
As you can see, it says nothing about WHICH module is missing. I tried for a few days to fiddle with dependant assemblies, web.config settings, etc. but only today I have been able to investigate and fix it. I downloaded ProcessMonitor from the Microsoft site and after defining the appropriate filters I tracked down the missing assembly: it was MSVCR71.DLL. Just found a copy on some other location on the HD, placed it into C:\Windows\System32 and it worked flawlessly.
I feel like I deserve a reward. Going to buy an icecream! :-)