Cant access my E drive

Hello,

Someone used my work pc in the weekend and when i came back on Monday i was not able to use one of the software ( buildsoft). My software shortcut was e drive and its a dongle.....when i click on the software it says window is searching for esw.exe and then further it says that the drive or network connection that the shortcut 'offsider estimating' refers to is unavailable, make sure that the disk is properly inserted or the network resource is available and then try again. i also tried using extension usb ports and then a message appears that please insert disk into drive E. I also cant view Drive E in disk management. its very important and i don't want to loose any data i don't have any backup for that. Can someone please help.........