Q: AFTER I DID THIS UPDATE MY SEAGATE BACKUP PLUS PORTABLE DRIVE IS NOT BEING RECOGNIZED!!!!

You might try reposting without the shouting.

CYBERLOU wrote:

The HD is not recognized by neither of my Apples.

Are both computers updated to 10.9.2?

Do you have a backup copy of your computer's hard drive prior to the upgrade in case you need to revert to it?

How are you connecting to the drive? USB?

MtD

have you checked disk utility to see if the hard drive shows up there?

you might try being more considerate of others, Arthur.

Do you see your boot drive on the Desktop?  If not check the Finder's View preferences and configure it as  shown below:

Even if the Finder isn't confirgred properly Disk Utility should see it as Apple Tech LT suggested.

OT

CYBERLOU wrote:

 

The disk shows up in the Disk Utility.When I plug the HD thru USB the Mac tries to read it but it can't, poping up a window that gives me three options:

Initialize.....Ignore....Eject.

Obviously, don't Initialize, that will erase all data.

Also, don't bother with the Seagate Diagnostics either.

Looks like you might have a bad disk. 

You may need to try a 3rd Party App like Data Rescue

But since you said that this occured when Mavericks was installed, first try a Mac with ML (if you have access to one)

Do as Tony suggested and see if another Mac, one without Mavericks, can read the disk.  If it can run Disk Utility on it to repair the disk.  Then try back on your Mac again.

You could try a data recovery application.  Go to MacUpdate.com and search for Data Recovery to get a list of potential candidates.  Some may have a demo version that you can run to see if it can even recognize the drive before you have to purchase it.