_usercap.dll is a windows registry file that is used with Cyberlink PowerCinema. This multi-media software is installed on new Dell and some other computers, and can be downloaded from its home site.
The file by itself is harmless. But if it points to the wrong directory, is still around after PowerCinema has been removed, or has been infected/corrupted by a virus or other unwanted software, it could be slowing your computer down.
.dll files work through Windows registry, which is basically a path for program shortcuts to pass through. The registry allows many programs to work at once without getting in each other’s way or bogging down system resources.
But a cluttered registry can equal a slow computer, which is one reason that Microsoft recommends that users re-install Windows once a year. Re-installing Windows is much less likely to be necessary for savvy users who clean their registries on a regular basis. ZookaWare PC Cleaner offers a free scan to anyone who is experiencing slow run times or frequent computer crashes (as well as for anyone who just wants to make sure their registry is okay).