Do you have the TNT patch intalled?
You should try running it in Softwaremode, without any of the TNTpatch installed. Reinstall the game, and try it that way first. Only, after it works in Softwaremode, should you try to run it in Hardwaremode and the TNTpatch.
The TNT patch can cause problems with the black screen, if you don't load it correctly.
What works is:
Just use the FF7config from the TNT patch.
Make sure the Test for 8bit pallet says Pass.
Select the Direct3d hardware mode.
Don't check any of the Riva options.
Don't use the FF7.exe from the TNT patch.
Alternate method:
Only if the 8bit pallet says Fail, should you use the FF7.exe from the TNT patch. There is a way to make it say Fail with Rivatuner. If you disable the 8bit pallet with Rivatuner, then you check the Riva TNT box, and use the whole TNTpatch. This used to be the only way to get hardware mode to work...but Nvidia fix their 8bit pallet.....so doing it this way is no longer done. Plus, Rivatuner only disables 8bit pllet on newer drivers, if the guy who writes Rivatuner updated it.....I doubt it's been updated. Rivatuner will tell you if it can't find the database for the current driver, if it says that...most likely it won't be able to disable the 8bit pallet.
It used to be:
disable 8 bit pallet with Rivatuner (I won't bother telling you how...but the option is buried in Rivatuner.)
Install the TNT patch. Both FF7.exe, and FF7config.exe.
Select hardware mode, and check the Nvidia option boxes....for TNT or the other one (can't exactly remember how the boxes are labeled...but you can't miss them).