Call Microsoft, tell them you lost your disk, they might be able to send you another if you can prove to them you bought it. If its a store bought comp without a official XP install disk then you will have to call the manufacturer of the computer and ask for restore disks for your model comp.
If the i386 has all the wpa stuff in it, you should be able to borrow a xp cd from someone, and after installing it, replace the i386 folder in the new install with the old one to get activated. This will only work if installed onto the same system the i386 or wpa files were pulled from.
Think that you'll need to be in safe mode to replace a i386 folder. Or slave the drive into another computer and replace files at will. There are easier ways to get activated, but they involve a phone call, net access of some type, or more detailed file finding.
If your copy is legit , go to this site below it will show you how to make a bootable CD with your existing i386 file to reload Windows. It is allittle involved but they will work, if done correctly. http://www.nu2.nu/bootcd/