HPOmlch.exe
(Hewlett-Packard)
This background program gets installed when you install the HP software suite for some of Hewlett-Packards OfficeJet printers, e.g. the OfficeJet 500. This program sometimes causes problems when you need to use parallel port devices, such as parallel port CD-ROM or Hard Disk drives, parallel port tape drives, etc..
Recommendation :
Not necessary. If you experience problems with the use of your parallel port when you are not using your OfficeJet, delete it using Startup Manager.