My Specs are:
Amd Athlon II X2 260 3,2Mhz
8Gb Ram
ATI Radeon HD 5750 1gb
Ugh...AMD & ATI
Ever heard of Intel? or nVidia?
Those companies make processors and video cards, too.

Okay, this sounds like another RADEON LOD (level of detail) and AA bug which has been around forever.
While common to see the MLAA option "greyed out" in DXGL when using some RADEON cards, it can (possibly) be indicating that there is no suitable Direct3D accelleration available. (This does not happen with nVidia FXAA cards - They all work)
You'll need to try a few things...
1) Check your driver version - Go to this page and carefully read the features and revisions with regard to AA, LOD, color distortions, etc.:
http://www.amd-drivers.com/download-RadeonHD5700-graphics-driver-for-Windows7-32bit.html2) You'll need to play with those RADEON settings (a bit) and turn down some of the "bells & whistles" features that are implicitly forcing themselves over the application.
3) Try setting WC3.exe compatability for "XP - Service Pack 2" and "256 Color" mode to reduce the ability for RADEON drivers to get too excited and screw things up. (again, not needed for nVidia)
4) You can read this (external) post and see some examples of RADEON problems when the LOD is out of control:
http://forums.bistudio.com/showthread.php?135165-Anti-Aliasingand this image from the above post:
http://imageshack.us/a/img801/686/aabug.pngthere is also reference to this post:
http://forums.bistudio.com/showthread.ph...466#post20814665) If you're using Windows 8 - Format your HD and use Windows 7.

Here are my settings with a little nVidia GT240 (512MB DDR5) on an Enterprise Linux Xen host serving a (virtual) Intel Core2-Duo 3.1GHz, 4GB Dual-Channel RAM (1.3GHz), running 32bit (x86) Windows 7: [Note - The same hardware and settings were used to make the DXGL video and all of the screencaps I posted above]
nVidia Global (no application specific settings required)
DXGL Global
DXGL WC3.exe
I hope some of this information helps to solve your problem.
--Decker