I get it installed and this is the error I get.

[Lucid]

the only thing that somehow seems to fit here by using the search function is:

It is being run as administrator, that's the very first thing I tried.

Edit: figured out the problem, after update my folder had BOTH d2ex2windowed.dll and d2ex2full.dll, I moved one of them out of the folder and it now works properly.

Have you installed Diablo 2 + Diablo 2 LoD and didnt log into the normal battle.net? And then have it updated manually to 1.13d patch (the actual patch 1.14 doesnt work)?!
Tryed running as admin? Tryed re-updating or reinstalling :x?

please be patient, that i just check the obvious things first. If this doesnt help you out at all, there may help just the answer of an Admin

gl!

~Lucid