Data recovery from External Usb Hard Disk. Hi i have a

Question

Hi i have a Seagate 40GB external hard disk which was attached with d Usb of my PC, it was working fine but one day i had tried to connect it with my Laptop. 1st it show that a new hardware found n started installing but after few min. it show that ur new hardware was unable to install. after that i had plug it out from my laptop n again connected to my previous Pc but now it not showing conneted to my PC. i tried pluging in diffrent PC but the Hard Disk is Not showing. than i had changed the Cable, Cassing but it doesnt help. 1 THING I WANT TO INFORM U THAT THE HARD DISK IS ROTATING WHEN EVER I AM CONNECTING TO PC BUT ITS NOT SHOWING. Is there any way i can Recover my Data plz help its v v v important. as soon as poss.