I use NUT for all of my UPS on Linux machines. There is a beta Windows port available. I have it working for two Windows 7 Pro 64 bit boxes.
Documentation on getting it working under Windows is sparse.
Downloaded NUT Windows MSI installer 2.6.5-6. Installed.
Copy libgcc_s_dw2-1.dll from bin to sbin. it is required for upsmon to run.
Grabbed a copy of libeay32.dll and ssleay32.dll from my Nmap install and copied these to the bin and sbin folders. Without these two files upsc, upsd and upsmon throw error (0xc000007b).
Downloaded libusb-win32-bin-1.2.6.0.zip from SourceForge.
Used usb-lib bin/inf_wizard.exe to create the proper .inf file for the UPS and installed.
You can use bin/nut-scanner.exe to see is the UPS is detected.
Edit the config files: nut.conf, ups.conf, upsd,conf, uspd.users and upsmon.conf.
To fully integrate into the network, I edited(on the appropriate systems):
/etc/nut/host.conf to add the new system to the list displayed in the web status display.
/etc/nut/upsmon.conf to add the system to the list monitored for status with email/text warnings.