The game was working fine until I reboot my computer and try to play again, now everytime I launch it instantly crash and stop to responding.
I already enabled the stereo mix and tried to start in compatibility mode and run as administrator, as I saw it helped some people, but none of that worked. I also try to install older drivers on my gpu, but still with the same problem.

Any ideas?

My game never starts, actually, giving me a .dll error message. It might be a corrupted system file on my end.

Both of you probably need to reinstall

Or...

try these:

Run Steam as Admin if you are using Steam version after completely closing Steam

http://steamcommunity.com/app/6060/discussions/0/613957600532345622/

http://steamcommunity.com/app/6060/guides/?searchText=crash+fix&browsefilter=trend&requiredtags%5B%5D=-1#scrollTop=0

for Windows 10:

set resolution to MAX and make sure anti-aliasing is off

other things you can try:

if you have a black screen, try this: http://prntscr.com/8288sp -http://oi65.tinypic.com/33m0x3d.jpg (screenshot)
- http://steamcommunity.com/app/6060/discussions/0/611703999972108103/

enable stereo mix

How to Enable Stereo Mix:
Start > Control Panel > Sound > Recording tab > If you don't see Stereo Mix, right click and select Show Disabled Devices > Enable Stereo Mix
(If you still don't see Stereo Mix, try to plug in a mic and enable it)
http://www.howtogeek.com/howto/39532/how-to-enable-stereo-mix-in-windows-7-to-record-audio/
https://www.google.com/search?q=how+to+enable+stereo+mix&client=aff-maxthon-maxthon4&channel=t28&gws_rd=ssl

if plugging in a mic or headphones into the mic port does not make Stereo Mix show up, try downloading:
https://www.google.ca/search?site=&source=hp&q=stereo+mix+download&oq=stereo+mix+download&gs_l=hp.3..0l9.2880.7537.0.7660.23.16.2.5.5.0.122.1212.14j2.16.0....0...1c.1.64.hp..0.23.1224...0i131j0i10j0i3.WjTPLCJ_DpA

run as admin;
go to right click on the entire SWBF2 folder (located here: C:\Program Files (x86)\Steam\steamapps\common) and going to:
Properties > Security > Edit > Choose your User > give it full permissions by clicking the Allow on everything there > Apply. > Advanced > Add Permissions if you like > at the top change OWNER to your main User. > hit Apply. > then go back to C:\Program Files (x86)\Steam\steamapps\common > click SWBF2 > GameData > right click on SWBF2 > at the top it should say Run as Administrator, try to run it that way, if that doesn't help, right click again > go to Properties > Compatibility > Run the program in Compatibility Mode. In Security make sure you have admin rights there also, simply go to security and check. click Edit to change Permissions, click Advanced to change Owner and more Permissions just like before with the SWBF2 folder.

delete vidmode

(vidmode is located here: C:\Program Files (x86)\Steam\steamapps\common\Star Wars Battlefront II\GameData\DATA\_LVL_PC )

plug something into microphone port

if your game only crashes on a certain map, go to: Library > right click SWBF2 > Properties > Local Files > Verify Game Cache
(this removes mods, etc btw if you have any)

if your game crashes on a modded map/etc uninstall it and reinstall.