I honestly don't know why HP hates its customers. They assume I want to use USB to connect a business printer, or want ~140MB for a driver, or want some other print management software instead of just a driver.
So here you go. The HP Color LaserJet 3600 64-bit driver for Windows 7, 8, and 8.1.
HP3600_64_Bit.zip (14.2 MB)