"1) Please make sure that you use "Run as Administrator" to install and to start the game (right click on the shortcut or setup file and select "Run as Administrator").

2) Please reinstall the game to a simpler path (like: C:\Games).

3) Install the June 2010 DirectX runtime package, then use the DirectX web installer, as your current DirectX may have become corrupt over time.

You can find the ZIP file containing the 2010 package installation files here:
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=3b170b25-abab-4bc3-ae91-50ceb6d8fa8d

You will have to extract the files into some folder, then open that folder and launch the DXSETUP.exe file in order to proceed with the installation.

Afterwards, download the latest DirectX web installer and use it as well:
http://www.microsoft.com/en-us/download/details.aspx?id=35

4) Please try the advice given in this forum post:
http://www.gog.com/en/forum/desperados_series/desperados_runs_slow_on_windows_7_x64/post6

5) If the above did not help, right-click the game's shortcut, go to Properties -> Compatibility and set different compatibility modes before launching the game again.

6) Please send me your computer's DXDiag.txt file, so I could look into this problem in more detail.

To launch the DXDiag application on Windows Vista or 7, click the Start button, type in "dxdiag.exe" in the text field at the bottom and press Enter.

In the newly opened DXDiag window, click "Save All Information..." and choose a location in which you want to save the file (your desktop, for instance). Once you have created the file, please attach it to a reply to this e-mail.

Regards
Genoan

GOG.com Support"

All credits go to the support team. The Direct X stuff worked for me. Thank you so much GOG you guys are awesome and now I can go back to enjoying a great game. :D

I really hope it works for anybody else with this problem.