This is what I did after couple hours trying to install the UPS Thermal Printer 2844.
Follow the steps in this order.
1.- Download the Zebra driver from this link.
Zebra Windows Printer Drivers.
2.- Unzip the file on his default folder.
3.- Open file manager a look for the file name DRIVERWIZARD.EXE (Computer:Windows:Seagull)
4.- Select the file, right Click and run it as ADMINISTRATOR
5.- On the Wizard Menu choose INSTALL THE PRINTER DRIVERS
6.- On Printer List go all the way down a select ZEBRA UPS 2844
7.- VERY IMPORTANT rename the printer name as UPS THERMAL 2844 Otherwise UPS Online will not find the printer.
IT HAPPENED TO ME that's why I expended some many time back and forth
Follow the prompts if the system ask for restart, restart the machine
8.- Plug your Thermal Printer to your computer
9.- Turn it on
10.- Wait for Windows install the printer by itself
11- If Windows ask for restart, do it again.
12.- Log on UPS.COM and try.
Good Luck.
It works to me after 4 hours looking for a solution.
Ps.. My Thermal printer was perfect on Windows XP.. I bought a new computer with Windows 7 64Bits that's why I have to install the Thermal on the new computer.