Please read this BEFORE registering PUM:
The number of printers Printer Usage
Monitor can monitor running on one PC, is limited by the hardware and
the operating system that you're running. The better hardware you have
P.U.M. will take advantage of it. Best performance has been observed
under Windows 2000 operating system. Maximum supported number of printers
per one instance of running PUM is 1000. To monitor more than 1000 printers,
P.U.M. must be installed on additional computers and use a DBISAM
database server (provided free of charge).
I strongly recommend to all those who are interested in P.U.M. to test it first.