Okay, a few things to try:
1. Re-installing, which you've done, so that's out.
2. Making sure the patch (1.3) is properly installed, it can be a bit shaky on install occasionally, so I've heard (make sure the patch downloaded properly too). Check which versions the game says it is running after patching, if you cannot see this because of your issue, right click on the .exe file and read what version it is.
3. Using something to stop background applications from 'stealing' video memory from it when it loads the graphics. The T-72 devs recommend using 'ENDITALL' or a similar utility to achieve this. Enditall is worth having anyway, even if this aint the problem.
4. Update your video drivers.
5. Tweek your video driver's setting, this is especially pertinent if you have an NVidia graphics card, as there are some known issue with T-72 and NVidia. Turning off some of the graphics card settings can sort this out (don't ask me which ones, I use ATI graphics cards!).
6. If your PC is overclocked, this can cause problems with T-72 apparently.
7. Long shot this one: Note that it is notoriously crap on multiplayer, so if it was an MP game you were trying, that could have been the issue.
Chock