If this is anything like Morrowind (which it probably is), ESM is a master plugin, and ESP is just a normal plugin. Now the bigger mods for Morrowind are better off using the ESM. So just use the ESM.
ESM are loaded first, so it depends if you have alot of mods installed, but usually your important ones go first. So somethign like that I'd say just use the ESM.
Now I have another problem I recently bought a new monitor and the colours look kinda weird when in a dark area I notice this when playing Fallout3 and Dead Space.Does this have something to do with the contrats? do I need to fiddle around with the monitor or do I need to change over the NVpanel?
The dark area for example on my rifle look slightly pixelated/purple ,I'm gonna make a pic brb.
Where the hell did you get this from? There are a bunch of mods that function using both masters and regular plugin files, especially the big ones. For example, Fallout 3's incarnation of MMM does not work without having both the ESM and ESP (the main one) active.
But seriously OP, check the readme or equivalent of the mod. With the... stability... of FO3's (and Oblivion's) engine installing mods wrong is the last thing you'll want to do. Well, at least the plugins are easy to correct most of the time.
If the ESM and ESP are named exactly the same (and you don't know if the ESP is optional or not) chances are you need to use both. Mod installation can differ a bit so always try to find info about the mod in question.