How is your scanner connected? It must be USB according to this. TC.
'What should I do now I have upgraded to Windows XP?
For your EPSON scanner to perform correctly on Windows XP you will need to download the relevant drivers. Please note: Windows XP does not support scanners connected by a parallel interface. You will need to use USB if available. If there are no XP drivers available for your product please use the Windows 2000 drivers.
To download the XP compatible drivers please visit click here. Then confirm your language and select Downloads. Once you have found the required driver click Save. When the file is downloaded double click it and follow the onscreen instructions.'
Go here for XP drivers if you need them.