Windows 7 and Pavilion ZE2000Windows 7 will automatically install the drivers you need. The main problem is you will need to install the graphic driver to get the maximum resolution and performance and also the audio drivers. This is because most ZE2000 uses Intel 82825/82855 GME graphic chipset which no official Windows 7 drivers released by Intel or HP. Further more, all ZE2000 model/variants uses Conexant AC-Link which does have an official support site which provide newer driver for old sound chipset.
ZE2000 Windows 7 DriversActually you only need to use the original Windows XP drivers, but it require a little bit modification before installation.
I already write a brief installation guide to install both audio and graphic drivers.
Audio Driver for Windows 7. : Drivers and installation
Graphic drivers: Drivers and installation
Others Drivers InstallationIf you have problems with the other driver do let me know. From my experience you will also need to install Card reader driver (if you want to use it). You can also use your original XP driver, just install it in compatibility mode or use the same audio installation method to install the card reader.
You wifi should work because from my experience windows will automatically installed the driver for it. Do let me know if you have problems with the driver installation.