it doesn't find the printer on the network.
On the driver download page the following "update" is available for your printer:
Windows 7 Critical Update to enhance reliability of network connection
"This update corrects an issue which causes network-connected printers to disappear from the system."
Since Windows 8 has not been released yet not all drivers are going to work with it. Some drivers are very specific about the operating system version, so you might have to wait until they release Windows 8 drivers (if they make them for your model).
You could try redownloading the drivers from HP, they might be corrupt.
Some drivers might be available using Windows Update.
It looks like you already tried this option:
Troubleshoot Compatibility
This can help with some (but not all) programs/drivers:
1) Uninstall the program if it's already installed. Then when you install/reinstall it instead of double clicking on the install file right click it and select "Troubleshoot Compatibility"
2) Then click "Try Recommended Settings" and in the next windows click "Start the Program" to install it.
3) After it installs see if it works correctly. Please note - some programs may not be able to run in Windows 8.
