Certain games not starting at all

Hi,

Suddenly a couple of my games stopped working altogether. I am talking about F1 2010 and DiRT 3.
When I start them, I have to confirm that I want to run them as administrator (as I always have, no issues there), so I do that, and then nothing happens. It's as simple as that, no errors, they don't show up in the task manager or anything, just nothing happens at all.

They are both racing games (and I use my racing wheel with them) so I tried disconnecting my wheel in case that was causing the problem, but no luck.

They are also both from the same company (Codemasters) but they're notoriously slow to respond on their forum and they probably won't know what causes it anyway.

I am just wondering, what could cause an executable to just stop working completely, for no reason? I played F1 2010 just yesterday, I did not change anything since then, hardware or software, everything is the same, except that the game just stopped working.

I tried installing new drivers, restarting the PC, nothing helps. I have never seen this before, executables just not starting at all? Sometimes they will start invisibly or in the background or something and fail to show their UI, but then they still show up in task manager and I can kill them and try again. Not this time, they're definitely not in task manager, nothing is started...


Help? Any idea's what I could try?

is there a scratch on the installation cd ?

I am not using any cd's. I am using a no-cd crack for F1 2010 because I lost my disc, and I bought DiRT3 via Steam.

Have you upgraded your pc since the games last worked?