If you have installed a pirate copy (AKA cracked) version of WindowBlinds 5, please be aware that the crack is faulty and WindowBlinds will cease to function correctly on your computer.
To fix this you just need to uninstall WB and if you wish install a purchased copy of WB, or the trial.
To uninstall, you can either wait for your computer to login, unload WB (either using wbconfig, display properties, or from a command prompt calling WBLOAD UNLOAD) and then uninstall WB. Or you can boot into safe mode & uninstall WB from there.
Your computer has not been harmed in anyway. Whoever made the crack did a poor job and patched out code that causes WindowBlinds to no longer be able to paint bitmaps (so title bars, borders, everything will be black).