Could still do with your system specs, really, just in case it is related to your graphics card or chipset or something. Users with similar setups might then be able to advise you if and how they resolved the issue.
As for your OS, you say you have Vista, but which version and is it 32-bit or 64-bit? It can make a difference.
I'll still try to make some recommendations, though, even with the lack of system information.
Firstly, uninstall the game completely.
Once done, re-install the game making sure that you right click on the installer and select Run as administrator (you should get a UAC prompt to which you should accept).
When the installer window comes up, do not install into Program Files or Program Files (x86). Use the options to install to an unprotected folder, such as C:\Games\...
When installed, try the game again. If it works, great, if not, try running the game by right-clicking the shortcut and selecting Run as administrator.