Grey screen w/ a question mark?

I was told by Apple that may harddrive would soon be giving out in a month or so & they quoted me at $160.. I fixed my other Macbook but wanted to have my other as a back up cuz I'm a dj so I changed the hard drive & now I get a grey or white screen with a question mark when I try booting up..How do I fix this? I run a 13" 2009 unibody w/ Mountain Lion 1.8.2 (I bought from iTunes) but have no discs that came with it works perfectly fine w/ the old original hard drive but has the question mark when installing the new one.. the new one is compatable w/ my laptop its actually an upgrade from the previous.. Please help with any info available, thanks

You need to install the operating system on the new drive.

Redownload 10.8, create a flash boot disk - easy way is Lion DiskMaker. There are plenty of tutorials via google for installing to a new drive.

Or you connect the old drive externally and boot to it, grab SuperDuper or Carboncopycloner and clone the old drive to the new internal drive.

thank you I will try that now.. I appreciate it

bobtomay said:

You need to install the operating system on the new drive.

Redownload 10.8, create a flash boot disk - easy way is Lion DiskMaker. There are plenty of tutorials via google.

Click to expand...

when I install the new hard drive in there are there any buttons I need to hold down? because usually it was either the question mark or a blank screen

bobtomay said:

You need to install the operating system on the new drive.

Redownload 10.8, create a flash boot disk - easy way is Lion DiskMaker. There are plenty of tutorials via google for installing to a new drive.

Or you connect the old drive externally and boot to it, grab SuperDuper or Carboncopycloner and clone the old drive to the new internal drive.

Click to expand...

Thanks!!

it worked I appreciate it!!

bobtomay said:

You need to install the operating system on the new drive.

Redownload 10.8, create a flash boot disk - easy way is Lion DiskMaker. There are plenty of tutorials via google for installing to a new drive.

Or you connect the old drive externally and boot to it, grab SuperDuper or Carboncopycloner and clone the old drive to the new internal drive.

Click to expand...