[{HVY-E}Jinxx]

I've found the best way to run IL-2 is to have it on a completely separate hard drive from the Windows install.
This is pretty much the best for any game you're going to play.

Setup Windows on one drive and have Windows use that drive for the swap file (virtual memory)
Setup the game on the other drive making sure to set indexing, system restore, and swap file to 'Off' for that drive.
Some people may recommend against disabling system restore for a drive, but I've found that there is a lot less disk activity if you set it to off for that drive.
If you have enough memory, you can also setup the swap file to run on a virtual ram drive instead of the hard disk. This will also help in overall performance of the system.

Hope this helps you out.

S!