why do I have a problem signing in to email on another computer and get a blue screen with rev48 at bottom
Your statement implies -
(a) you have no problem accessing mail from your own computer, and,
(b) you have a problem accessing mail from A N Other computer.
Is this a correct interpretation - Yes or No?
Further info needed -
1) webmail or through an email client such as Outlook?
2) have you tried more than one A N Other computer?
3) do you get any error messages other than - “a blue screen with rev48 at bottom”?
4) is the A N Other computer used to access any non-VM email system?
Note - The "Blue Screen of Death" was a common problem on older versions of Windows.
See - https://en.wikipedia.org/wiki/Blue_Screen_of_Death
Which version of Windows does A N Other use?
rev 48 is likely a reference to the revision of Open-Xchange and maybe seen when Virgin Media's customisation are not properly applied.