If you are currently running Vista or Windows 7, please complete the instructions in the following link:
Title: Windows 7 and Vista Troubleshooting
Link:
http://support.steampowered.com/kb_a...5688-IFHZ-2170
If you are running in Windows XP, take the following steps:
1) Exit Steam.
2) Go to the "Start" menu, select "Run", type "regedit" and click "OK".
3) Navigate to the following registry key: HKEY_CURRENT_USER\SOFTWARE\VALVE
4) Right click and select "Permissions"
5) Check the "Allow" boxes for "Admin" and "System" for both "Full control" and "Read".
The remaining steps apply to *all* versions of Windows.
Please also verify the GCF for this game as outlined here:
Title: Verifying Game Cache Files (GCF)
Link:
http://support.steampowered.com/kb_a...2037-QEUH-3335
Note: Files may fail to verify. This is normal and can be ignored.
Then test the issue.
If you still have difficulty, you may also need to manually run secondary installers required by this game.
Exit Steam entirely.
Browse to your Dark Souls: Prepare To Die Edition installation folder (Usually C:\Program files\Steam\Steamapps\common\D:Steamsteamappscommo nDark Souls Prepare to Die EditionREDIST\)
Run the following installers:
...\steamapps\common\Dark Souls Prepare to Die Edition\REDIST\DirectX\DXSETUP.exe
...\steamapps\common\Dark Souls Prepare to Die Edition\REDIST\GFWL\gfwlivesetup.exe
Reboot your computer and test the issue again.
If the issues persist, please complete these guides:
Title: This game is currently unavailable
Link:
http://support.steampowered.com/kb_a...4595-WEXN-6831
Title: Games do not run after 'Preparing to Launch'
Link:
http://support.steampowered.com/kb_a...6218-USFX-5568
Further support for this title is handled by a third party support department - please follow the instructions below to contact the support provider to troubleshoot this issue:
Dark Souls Support
http://www.namco.com/support"