Snacko's right Pooka. If your new machine has the 64-bit version of Windows 7, you will find two folders on your C: drive named 'Program Files' & 'Program Files x86'. The 'Program Files' folder is for 64-bit applications only, all the 32-bit apps (like IL2) go into the x86 folder. (If the PC is on 32-bit Win 7 then you just get a 'Program Files' folder. Obviously 64-bit applications will not run on this OS). Rather than installing IL2 afresh though, I'd be inclined to make a copy of your game folder on a memory stick or external hard drive, and copy the whole thing to a new folder (for example mine's in e:\IL2 Downloads\).
I'm not sure how your rig is set up Pook, but I would suggest you try to use 64-bit versions of drivers and software where possible. For example I have the 64-bit version of the Saitek software for my X52, and my headset also has 64-bit drivers, although I've yet to see 64-bit software for TrackIR, so I'm using the 32-bit version and it works fine. For what it's worth, I feel that Windows 7 is so flexible and versatile that I really don't mind the very slight inconvenience of needing to change the installation folder for IL2.
Jabo