I have a 1tr verbatim hard drive that's always worked fine but now all a sudden is unrecognised and doesn't show up in my computer or device manager anymore, usb ports work fine with other devices, have tried different cable and still nothing.. please help, do not want to lose data!

Have you tried reinstalling the drivers for your external drive ?

try to insert your usb hard drive in other computer! If it is read by other computer, the problem is in your computer.. uninstall all the usb drivers from your device manager and reinstall again..

but: if the other computer doesn't recognized your usb hard drive, maybe you try this!
1. format your usb hard drive
2. use and recuva installer( try to download it! Its free and virus carried.)
= this.. application can recover deleted files..