I understand that you are unable to scan after upgrading the compuer from ME to XP.
Please follow the below given instructions to resolve the issue.
Check for the communication between the computer and the printer as scanning needs bidirectional communication unlike printing.
To isolate the issue I suggest you to try scanning from the Windows Image acquisition(WIA) wizard on the computer.
Follow the below steps to Scan using WIA
1.Verify that the all-in-one product power is turned on and the printer cable is properly connected.
2.Click Start then Click All Programs then Click Accessories then Click Scanner and Camera Wizard.
3.Follow the Scanner and Camera Wizard instructions to scan images to the computer.
If you are unable to scan using WIA, confirms that the issue is with USB drivers, please follow the below given instructions to refresh USB drivers:
1. Save and close all programs that are currently running.
2. Click Start, select Shut Down, and choose Restart the computer.
3. Press the F8 function key, this will display the Windows Startup menu.
4. Select Safe mode.
5. After Windows loads in Safe mode, right-click the My Computer icon and select Properties.
6. Select the Hardware tab and click the Device Manager button.
7. In the Device Manager Window, double-click the Universal Serial Bus controllers.
8. Right-click the device listed under Universal Serial Bus controller and select Uninstall.
9. Click OK to confirm the removal of the device.
NOTE: Repeat steps 8 and 9 until all the devices under Universal Serial Bus Controller are removed.
The USB port is now uninstalled.
Now, restart the system. The system automatically detects and reinstalls the USB port.
Then try scanning from WIA and if that works try scanning from HP Director.
Please click on Start>>Programs>>HP>>HP Director.
If unable to scan from HP Director, search for the file " hpqscnvw " in C Drive which is the executable file for Scanning.
Double click on My Computer to open it > C Drive > Programs files > HP or Hewlett Packard > Digital Imaging > Bin Folder. Check for the file " hpqscnvw " there.
If found double click on the file to and try scanning. You can also save the short cut of the file to desktop and can use that file for scanning.
Run the scan diagnostic utility to resolve the issue.
Just copy and paste the entire link into the Internet browser's address bar and press enter
If you are able to scan from computer, then follow the instructions from the below given article to scan from the printer front panel.
Here is the web document:
Just copy and paste the entire link into the Internet browser's address bar and press enter.
This should resolve the issue that you are experiencing with.