OK, download pocketputty from here:
http://www.pocketputty.net/
run putty.exe on your phone
change the box that says SSH to Serial
change serial line to COM9:
in the serial tab change flow control to none
click open
type ATV1
It should reply with OK, if not, close and try again perhaps with a different speed, 9600 worked for me though.
type AT+HTC_RMSL=0 in capitals
and it will reply with your MSL.
I had to reset the phone before it would work in the ##778 menu.
Hope this helps.