MacBookPro hard drive replaced. Parallels 9 died.

I have a 7 year old MacBookPro laptop with OS X El Capitan installed. I had Parallels 9 and Windows XP installed on it. Recently, the hard drive had to be replaced. Done by an Apple certified technician that I was referred to by Apple Support. Reloaded from a Time Machine backup.
NOW Windows cannot be brought up. Parallels, although present on my desktop, says that Unable to connect to hard disk 0.
When I click on a Windows file I see "Specified file cannot be used as a virtual hard disk."
When I try to run BootCamp assistant, it wants me to insert the WindowsXP installation disk which it doesn't seem to recognize.
I have downloaded the Windows files and put them on a USB memory stick that is always plugged in to the computer.
I have put the windows XP iso file on the memory stick
I have read many of the forum answers, but have not found an answer that works for me.
I don't know what to do. I need my files back.
Apple Support says that they can't help me.
Can somebody help?

 

Hi RobinR1,
Please try with any previous Time Machine backup and check if it works. If the issue still persists, please follow the steps below:

1. Use your Windows XP ISO and install Windows as a fresh copy by referring to this article.
2. Transfer your files to XP from your USB Memory stick and check how it goes.

 

Thank you Arun. I got Windows successfully reinstalled, but how can I get back the programs and files that were on the windows desktop?

 

Hi @RobinR1, in order to get the Windows application it needs to be reinstalled.