when i play in windowed mode i get errors like every 2 secs.
these errors say: The application has failed to start because MagCore.dll was not found

so how do i fix this..?

That has nothing to do with Morrowind itself.
Google "MagCore.dll download" and search for the file and download it, otherwise, search AOL’s help files and support section.

Running the game in Window mode isn't as stable as Full Screen. Keep that in mind, too.

why search aol....?

and download it and put it where..?
will the game find this file in my documents or what..?

ao this MagCore.dll isnt something to do with morrowind then..?

cause i only get the messege when i play morrowind in windowed mode. i done get it when i play full screen

Correct, nothing to do with Morrowind itself.
I mention AOL because the problem arises often with AOL users.

There is a great search engine called Google. Use it to search for "MagCore.dll" and you will quickly find solutions.

MGE has issues as well with windowed mode. I never use it. I like performance to much.