Is it possible to transfer an iphone backup from one Windows pc to another?
 

iTunes 12.1.2.27 64bit on Windows 7
iPhone 6 plus 128gb

I updated to iOS 8.4 yesterday (while Apple are still signing it) which involved doing a backup before hand, I did this on my older pc and it seemed to all work perfectly fine. Before reading any further please note I have no interest in updating to iOS 8.4.1 as yet.

Now restoring the data and apps is giving me grief, it's as if the phone keeps disconnecting mid way through copying apps with an audible chime.

Occasionally it will throw an error on the PC screen:
iphone cannot be synced. An internal device error occurred


but it does not always show that error, other times it just goes back to step 2 of 5 in the sync process, preparing apps to sync seems to take an age, but I've got 231 or so apps.

I've tried various things like using a different cable and usb port, cold-booting the PC and no real improvement, and it's getting on my tits now. I sat there nursing it, and spotted that just before it fouls up the light at the rear of my usb mouse flickered. Now it's making me think maybe my PC is being a prick rather than iTunes / iPhone...

Is it possible to transfer an iphone backup from one Windows pc to another? If so I think I'll try that as my i7 PC has usb 3 etc...

Yep, solved.

To answer your original question. Yes, you should be able to move the backup file from one machine to another. Here is the support doc about finding backups:
https://support.apple.com/en-ca/HT204215

All you would need to do is to find that location on the other PC, then copy the backup file over, and iTunes should then find it and allow you to restore the backup.

You might need to copy all the music over though, but then I don't think that is part of the backup anyway. Worth having a read of this discussion thread:

https://discussions.apple.com/thread/4214342