Hd 750g wd sata2 32m wd750aads in external case has no drive letter

 new external roswell case up to one trb has one power supply new wd 750 drive drive powers up pings puter when turned on  just won,t show up in computer drive with other drives have run windig on drive test good  drive has no jumper  am running vista 32bit home prem the drive show up as a wd 750 in addmen tools and in windig just has no disc letter their for can not access drive wd teck supp sad put jumper on 5 to6 pin and try don,t have a jumper can get one i have 2 500 gig ex drives and 2 300 gig exdrives  all working good when pluged in the wd750 has not had anything done to it no drops no format no partitions, hard to do when can not access drive i know it needs a drive letter to show in computer with other drives what do i need to do thanks

after getting head out of behind i click start to control panel to adm tools clicked  to computer management to disc management  found disc the wd750  hy lite then intlize it give it a drive letter[got to have drive letter] then formated[got to be formated] took long time 5 hours said was in RAW not NTFS but let finish formating after it was formated here is what it said ,new volume  H  health [primary partition]   698.63 ntfs .the drive is working fine now, if all fail,s turn boot over read instruction on heel,old saying can not pour pee out of boot with instrutions on heel

That formatted size should be correct.  Glad you were able to figure it out for yourself.