Here's the link to the x63 product page. Notice that it says to uninstall the driver and then upgrade to Windows 7. Since there is no driver for Windows 7 there, you cannot use this printer with Windows 7 UNLESS Win7 automatically can find a driver for it. To try that, open Windows Update, click "Check for Updates", and see if it finds anything at all, even an Optional Update. If it does, install any printer driver you see. Now open "Devices and Printers" and see if the printer shows up there. If not, then I don't think there's anything else you can do.
(If you can't use your old printer, you're not alone. In upgrading to Win7, I lost compatibility with my Canon Multipass F30; unfortunate, because that model has "compatible" ink available that works very well for very little money.)