A word of warning:
My GTL on Windows 7 64bit didn't fully work for me with the crack so I had to cram in an XP install for this purpose only. Seeing the new digital download version, I thought I'd take a shot at it and could hopefully delete the XP install. NO SUCH LUCK. Still the same problems so beware - a waste of 10 euro.
Just to be clear, the main game on it's own runs fine, as it did with the crack. The problem I've got that makes it useless with our leagues, is that certain add-on cars mess it up (and I've seen other people also with this problem). For example, no matter what car I select, the modded BMW 2800CS is what I get. If I delete the BMW then I'm always given the modded Abarth 1000TCR and so on.