If you install Sudden Strike forever, a Sudden Strike addon, in the main menu it will show 1.21 version. Depending on your version, this is the final patch.
,,Sudden Strike Forever was an official add-on to Sudden Strike which introduces many more historically correct units and equipment, such as the upgraded Soviet T-34 tank (1944 version). New terrains are also provided: a desert terrain for the British missions in Tobruk and Tripoli and snow terrains for Soviet missions. The expansion also polished the game engine, balanced the damage of certain units, and added a map and scenario editor.Source from wiki.
The add-on includes 4 inter-linked scenarios for each of the campaigns for the Germans, the American, the British and the Soviets. Other units which are added into the add-on includes, but not limited to the Universal Carrier for the British; the BR-5 artillery, 160mm grenade launcher for the Soviet forces and more. The supply system has also been tweaked with artillery crews automatically resupplying themselves with ammo crates nearby instead of relying on supply trucks to do the job. The supply trucks would still be needed to repair damages inflicted on these artillery units, however.,,
Sudden Strike 2 :
Install the patch from Fileplanet gaming site.