Simply drag-and-drop the compressed executable onto UNP. Unlike UNLZEXE successful decompression is not heralded by the creation of a .OLZ file, instead the affected file will increase in size. If a batch file with a pause command is used the program itself can be seen to confirm decompression. This works on most windows systems up to Windows Vista. Otherwise it must be run in DOSBox using the following commands:
Z:\>mount c "C:\the directory\the game is in" Z:\>c: C:\>unp keen1.exe
In all cases the old, compressed file is overwritten unless switches are used.