the following was taken from
here but since I wanted to make sure I had this for myself and in case the original link stopped working I am adding it here.
1. If your scanner is connected to your computer (USB) uninstall it using the device manager, be sure to check the box that says "delete the driver."(This option seems to only be in Vista) Unplug the USB when it is uninstalled.
2. Download the sj652 installer packaged from HP.
here or
here
Extract it to a folder.
3. Select the "setup" app and right click on it to get properties. Change the compatibility to XP. Then run it and click "OK" on any warnings from Vista.
4. Now, go to the HP folder in your Program Files directory, there will be a "HP PrecisionScan" folder. It will be the only one unless you have other HP products. Open the PrecisionScan LTX folder and change all apps to XP compatibility.
5. Plug in your scanner via USB and let it install.
The scanner will now work using the LTX software installed on your computer. Like I said, the buttons on the front do not work, and you can't do anything with it by going to "scanners and cameras" in your control panel. Windows Fax and Scan also does not work. BUT, it seems to work great and all the functionality is there in the LTX software.
Thanks to anskyber.