2nd hdd not showing up in my computer

Hello,
ive seen a few posts regarding the problem which i am having but none which can help fully. i was having a few problems with my desktop so decided to do a factory reset but just using my recovery discs instead of the restore from back up from my external hard drive. everything went fine and when it rebooted my 2nd hdd which i'd had installed was showing up as (x) instead of the (d) which it had been before, then my desktop rebotted again but this time it showed no 2nd hdd in my computer. it shows up in disk management but does not allow me to right click and format or partition it just pops up with a help link. it's coming up as disk 1 and online and healthy but just not allowing me to use it at all. ive got all the data backed up on my external hdd so not bothered about formatting, i just want to be able to use it again. im quite a novice at all this so any help would be greatly appreciated, thanks danny.