How I went from ripping my hair out, to MW bliss..
1: Install Crysis Wars and update it to patch 1.5 (Google for a DL link)
2: Run Crysis Wars -> multi-player -> internet games. First you will be prompted for a cd-key. Then a log in: Create a Gamespy ID (You may also get shunted to MyCrysis, I made a profile there too just to be sure).
3a: Run the MW:LL installer, then go into the file directory. It will look sort of like. Electronic Arts/Crytek/Crysis Wars/Mods/Mwll. Inside that folder is one called Updates. Extract the zip inside, then cut/paste the files into the Mwll main folder (There are file folders in there that will match up to overwrite old files, you'll know what I mean when you see it).
3b: Run the MW:LL Launcher again (I did this from the Mwll folder and made a shortcut from there, as Desura seemed to just want to keep crapping itself, but got he basic install done nicely) Make sure Auto update is checked, update it until it hits version 0.4.9. You must manually do this one update version at a time... (This took ages for me with a horrid DL speed
4: Run Crysis Wars: Select Mods from Left side menu. Activate MW:LL. Go to Multi-player -> Internet. Join a game, welcome to the war.
For x64 Users: Look into the Windows C++ fix for 64bit systems linked above. I ran this also.
btw Half of this insanity I had to figure out myself, you guys might want to smooth this out to increase your player base