Cannot get windows xp back on to my computer.

Assuming the computer has a Microsoft XP product code tag on it (so you can be legit & legal), see if you can borrow an XP installation CD from a friend.

Sometimes the reinstall is set up on a separate partition on the hard disk, which of course, is totally useless if the hard drive has failed in a catastrophic way.

You could also contact Packard Bell (I thought this company was history), to see if replacement disk(s) are available. Have your computer's Model & Serial handy. The disks won't be free, but likely much less than a Walmart etc, supplied edition.