I think some thing daft is being done by me and here is what I'v been doing.

Loaded a new PC with Mach3 drag my old XLM file over to the new pc. But all my files in the back up file are XB files, in the read me file it says If you would like to use one of the backups simply change the files extension to .xml and place it into the Mach3 Directory ? I'm sure in the past iv just dragged out the last good file I wanted to use in to where I installed Mach3 deleted the old one and booted up Mach.

It seems iv done some thing very wrong this time because I cant get any thing to load other than a unset up screen.

what am I missing I thought I was good at this until this evening.

Don't transfer the backup xml.
Instead, transfer the actual xml for the profile that you want from the Mach3 folder .... not from the backup folder.
Russ

If I understand you right none of my files are XML they are all XB files I even tried replacing the hole folder and still this never worked.

Never struggled with this before

Should I be moving a file or a folder and if its a folder what is its name

Don't even look at the Backup folder or any other folder in the Mach3 folder.
In the main Mach3 folder is the XML for your profile.
Copy / paste or drag / drop it to the new machine.
Rename it if you'd like or overwrite the existing.
Yours might be named differently (custom), just grab the proper one.
Russ

Thank you I cracked it even played with the exe. file to get it to load with out having to use the loader. 

Having not had to change any thing for 4 years didn't help you forget basic stuff after a while thank you once more