Mac pro cannot see external drive

Ever since I upgraded to Lion my 2006 Mac Pro 15" cannot see my external back up drive. I've seen people with the same problem on line but I've yet to come across a straight answer. I've wanted to re install the Lion software but A: I can't make a new back up because my pro won't see it B: The supposed recovery portion of my hard drive that should have come with the Lion upgrade doesn't appear to work when trying to boot up with the command "R" keys held down. I've tried it several times to no avail…..is there a straight answer out there???

G'day and welcome to the forums.

You do mean a MacBook Pro and not a Mac Pro one takes it?

Suggest you do a clean install of Lion after backing up your hard drive and transfer items over using Migration Assistant. You can download another copy of Lion f.o.c. going into App Store, hold down Option and hit Purchases, click on Lion icon and download. Then burn to a USB thumb drive. To access Recovery, hold down Option after booting.

Sorry, should have been more specific…it's a Macbook Pro bought in 2006. Also didn't mention that I replaced my old drive with a new 750 gig and upgraded the ram. It was installed by an authorized Apple dealer (I'm a bit of a geek but not enough to chance screwing up my gear). But as I mentioned, I can't do a back up because the Macbook can't see the drive.

Hi Bagman30,

I am having exactly the same problem by the sounds of things. Have you tried the advice by harryb2448 yet? Has it worked?

Good luck with it and I would be grateful if you could let me know either way.

idtbrian