PlayOn has to be installed on the same drive as Windows--usually your C: drive. If your C: drive is short on space, and you want PlayOn to use a different drive for temporary files, you can create a symbolic link with our Junction Helper tool (attached)

That tool automatically downloads a Microsoft program called Junction and makes a "symbolic link" from C:\Documents and Settings\All Users\Application Data\MediaMall\Media (on XP) or C:\ProgramData\MediaMall (on Vista and above) to your preferred drive partition.