"FIX the problem Microsoft."
The problem is not to do with Win10, but you could say Monopoly$oft is at fault.
There are some details missing from DaRedWolf's posts that may lead to other issues, but...
This is one of many games that used MS's much reviled Games For Windows Live.
After years of GFWL causing problems MS unceremoniously dumped it a couple of years ago,
which has caused new problems.
- Fortunately DIRT 3 is one of the few games with a GFWL problem that the games publisher has made it
possible to redeem your disk key code for on Steam ( you get the 'complete' version with all DLC ).
Note that Steam is no longer Selling this game, so it won't come up in their store, but you can still download
it after you redeem the code
( I had not bothered changing as I was already using an xliveless fix/hack, but I entered my code a few minutes
ago and Steam has made the game available for download on my account. )
The title of this thread said 'can't run'. Maybe not for the OP when he posted over a year ago, but
I've never had a problem running my disk based version of game on Win10 ( I've used an xliveless fix since
first installing the game on Win7 ).
The xliveless fix does not work with on line play, and while I don't get any ghost car off line, the game
has saved my progress.
- While I have been able to run the game on Win10, some games have an issue when changing Windows versions.
I had this problem with Batman AC, and had to redeem it on Steam to get it to run again. I lost my 42%
progress, but the Steam version was the GOTY version, so I got the extras I didn't have with the disk.
Win some, lose some. :)
.