How to Fix Prince of Persia: The Forgotten Sands Black Screen

METHOD 1:
Open regedit, search for Software->Ubisoft->Prince of Persia – The Forgotten Sands->1.000000000

Right-click the folder called 1.000000000 and rename it to 1.0. Or rename 1.0 to 1.000000000.



METHOD 2:
-Right click “Prince of persia.exe”
-Properties
-Compability


for Windows XP/2003: Choose Windows98 – ME mode and run in 800×600 mode.
for Windows 7/Vista:  Choose WindowsXP SP3 mode and run in 800×600 mode.




Source