lately whenever i try to play the game crashes... i will be selecting single player or loading a new area or something and the game will just freeze and i have to restart my computer. can some one tell me what i should do. ( oh and by the way a message saying " run time error " often appears ).

I think your best bet is to reinstall.
It's kinda difficult to say what the problem is.
Did you use the last patch? Did you install any mods?

i do have mods installed and no i dont have the patch but it has seemed to right itself now ;) . Though i am unable to go to the underwater city since the guthyankie captain wont die and therefor the game wont progress....another bug.

It would be a good idea to get the patch and baldurdash fixpack, anyways. It fixes many bugs and problems that you might run into.

Its really helpful, and makes the game slightly more challenging. which, in my opinion, is better