Everyone is wrong. It can work on Vista. If your firmware is 1.60 or above (the number in the top right on action replay main menu), then I can help you. Go to http://datelcustomerservice.com/ and on the left, click Nintendo DS, then Action Replay DS. Go to the bottom of the page, and click the LAST answer. Scroll down the version 1.60 and above, the non vista solution, and download the file they give you a link to. Extract it somewhere you can access easily, and be sure to have code manager installed and your Action Replay plugged in and your DS on.
- Go to Start>
- Right Click Computer>
- Properties>
- (On Left) Device Manager>
- USBIO Controlled Devices>
- Right Click NDS Link>
- Update Driver Software>
- Browse My Computer>
- Let Me Pick>
- Click NDS Link>
- Have Disk>
- Browse to the folder you extracted the files to>
- Press OK>
Let it install. Once it installed, open up yer code manager and it should find your DS =)