I just posted a beta version of ABR with Windows 7 support. I have not been able to test it myself (no access to OEM Windows 7 at the moment), but I have had a few beta testers who reported it worked correctly.
Give it a try if you are willing to help test it and please let me know how it goes.
When you run the backup, you should have 2 new files created in the folder, "backup-key.txt" and "backup-cert.xrm-ms". Make sure both files contain something, then save everything to a safe place before you clean install.
ABR (Activation Backup & Restore)