OK, now I know what's giving you problems. Your graphics card uses (shared) system memory, which is good enough for regular tasks, but very bad for games. I'm sure you'll have problems with any graphics-intensive game. M&B native isn't the most demanding game when it comes to graphics, but TLD is a tad heavier than native.
Shutting down any other programs might give you a small performance boost, but you'll probably still have problems running games on that machine.
Besides shutting down other programs, you can try lowering/disabling all graphics enhancements in M&B configuration panel. Change your game screen to 800x600 too, that should help.
You can also google for some info on how to improve your system (OS) performance. I think there's a good topic on Taleworlds about setting up Windows to give you better performance, search for it.
It's here: http://forums.taleworlds.com/index.php/topic,13083.0.html
Forgot to say you don't need to uninstall any programs, just shut down anything running in background before you launch M&B. It's safe to shut down any antivirus, anti-spyware and firewalls, if you disconnect from the internet before you do it (unplug the modem cable from your computer if you have to). Just remember to turn them up again before you connect to internet (you may want to place shortcuts to those programs on your desktop for easy access).