That is an old scanner, and I see two options for you:
1. Trash it and purchase a new scanner.
2. Install XP into a virtual machine (Win7 Pro XP mode, VirtualBox, etc.) and connect the scanner with a USB cable. You can then scan in XP and copy the files to Win 7.
If you don't have Window 7 Professional or better then you can't download the free Windows Virtual PC software and set up XP mode. I still like my 4400C and for the amount of scanning that I do it is fine. For those with Home Premium (32 or 64) you could set up another partition with XP as a dual boot. However I have found it simpler just to use one of my older small drives with XP installed on it and just boot up into that one if I am going to be scanning. Certainly it is not as elegant as having XP Mode, but for occasional scanners it is a simple no cost way around the issue.