Read lots of Windows 7 threads but couldn't remember the exact thread, and was unable to unearth it in a search.

I'm told Windows 7 will install ( upgrade ) over Vista without requiring a re-format. Is that true and will it mess up the present IL-2 '46 game?

Yes, you can update your Vista install to Win 7.

It "shouldn't" cause any problems and you "shouldn't" have to re-install anything.

However, I'd still advise that you do a format and 'clean' install, especially if you have been using that Vista install for sometime now and have a number of applications. The more applications you have on a system increases the possibility of having issues.

Even then, it wouldn't mean a re-install of IL2 1946. IL2 is one of the few games that doesn't really need to be installed on a particular OS or need registry entries to run. I have IL2 on my O: partition, which is strictly for data. I can, and have, run it from any number of partitions/OSs where I have a mix of XP, Vista, and Win 7 OSs installed.

All I need to do is make a shortcut to the desktop of the partition(OS) that I'm in, and the game runs just fine.

If you are worried, just make a copy of your current IL2 install to a different HDD, or to a different partition on your HDD if you just have one.

Quite true.

I can run my IL-2 1946 (US Retail version without SecuROM)

using Ubuntu 9.10 and Wine directly from my XP partition. The same is true for my Win7. I can run it directly from my XP partition, although I did install under Win7 in c:/Games also, so I could compare the two. In Win7 x86 (32 bit) just install outside /Program Files/ by running a.exe off the DVD. No compatibility mode or other special treatment is needed as long as you have the US retail version.