Can someone tell me the best place to purchase the PC download version as the DVD is no longer obtainable.
I've looked at Codemasters site which refers me to Steam site, what's that?
Where are you located? Some options, even Steam (as you may see if you read another thread very close to this one), are not available in every country.
You have to log into a Steam account. Some steam games can be run by just using the executable in the install folder, F1 2010 is not one of those games however. If you buy it through Steam you will have to use Steam.
If you don't end up finding it elsewhere for a reasonable price, I can assure you that in 7 years of using Steam I can't recall it causing me an issue. My net has not always been the most reliable in that time either...