12-28-2011, 05:53 PM

I have got a macbook pro and recently installed Lion. I now want to format my hard drive but when I follow the instructions that I have found online it does work. It tells me to go to disk utility and select the drive to erase and go from there, but when I select the drive the erase button on the right side is greyed out and I can't push it?

Any ideas?

12-28-2011, 07:00 PM

You can only erase or reformat/partition a drive when booted from Some Other Drive. That's why keeping Install DVDs is important - you can boot from it - then don't Continue the install - instead, find Disk Utility in the top Finder menus and use it to erase/reformat.
Does that help?

12-29-2011, 09:07 PM

I will give that a try tonight and let you know how I go. By the way the only bootup disk I have in Leopard not Lion that I have installed off the net. Does that make a difference?

12-29-2011, 10:27 PM

Probably will as most upgraded to Lion from Snow Leopard. You can go back to the App Store, hold down the Option key and hit Purchases and see your Lion purchase there. Select that and download another copy f.o.c. and then burn to a USB thumb drive. Instructions will be found if you use the Search function.

12-30-2011, 02:02 AM

Originally Posted by wil_sch

I have got a macbook pro and recently installed Lion. I now want to format my hard drive but when I follow the instructions that I have found online it does work. It tells me to go to disk utility and select the drive to erase and go from there, but when I select the drive the erase button on the right side is greyed out and I can't push it? Any ideas?

Did you boot to the Lion Recovery partition first? Hold down the option key and reboot, then select the Recovery partition. After it boots to the Recovery partition, select Disk Utility. Now you should be able to erase the main partition. If you're wanting to erase the entire drive and go back to Snow Leopard, you'll need to boot from the SL DVD and use Disk Utility from there.