StarForce usually includes protect.dll, protect.drv and protect.exe somewhere in the game directory. The icon on the .exe file is that of an application window overlayed with large golden-yellow key.
May also install following low level drivers: prohlp02.sys, prosync1.sys, and sfhlp01.sys.
StarForce may have issues if you have [[link:http://en.wikipedia.org/wiki/Data_Execution_Prevention DEP]] turned on, so you need to add the game's executable to DEP's exception list in case the game crashes or plain old refuses to work right at the start (when the copy-protection check kicks in).
The low-level nature of the copy-protection mechanism has caused great deal of anguish to all people, especially legal owners of games using it (the only ones that matter, really). Since compatibility with all manner of drives and other things there is unlikely to be accomplished in such a software in timely fashion, there have been reports of even drive failures, but most common perhaps is that it truly interferes with normal operation of the O/S causing more common kinds of problems, such as slow-downs, decreased system stability, false positives, and originally also the impossibility of uninstalling the drivers without great deal of effort from the end-user, [[link:http://www.onlinesecurity-on.com/protect.phtml?c=55 a removal tool]] was introduced silently at some point.