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onmi

macrumors newbie
Original poster
Jan 5, 2011
27
0
Hey guys, I had Lion installed on my 128GB SSD drive and I was wondering how I could do a clean install...? I made a boot USB drive of the Mountain Lion installer, booted from it, launched disk utility to wipe the hard drive clean and everything was just greyed out.

Any ideas how I can wipe the hard drive clean and install Mountain Lion?:eek:
 
It's seem like you took the proper steps. Boot from the USB and use disk utility to erase the Macintosh HD and then install mountain Lion.

Make sure you are booting from the USB and not the recovery partition. Hold down option to select the USB on boot
 
It's seem like you took the proper steps. Boot from the USB and use disk utility to erase the Macintosh HD and then install mountain Lion.

Make sure you are booting from the USB and not the recovery partition. Hold down option to select the USB on boot



That is exactly what I'm doing. I hold option, select the USB drive, boot, open disk utility and when I go to the hard drive there it wont let me erase it or anything:(
 
That is exactly what I'm doing. I hold option, select the USB drive, boot, open disk utility and when I go to the hard drive there it wont let me erase it or anything:(

if its an ssd just repartition it.
 
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That is exactly what I'm doing. I hold option, select the USB drive, boot, open disk utility and when I go to the hard drive there it wont let me erase it or anything:(

Yeah, that's odd. Try using your recovery partition utility to first erase it and then try it again using the USB utility.
 
Also I wanted to askabout clean installs. I would like to install ML today via a USB stick I will make.
BUT I don't want to lose my windows 7 partition and all it's files in the process.

I forget if I can wipe my Mac OSX partition and do a fresh ML install or if I lose my windows 7 by doing this?
 
I did this yesterday.

Went to supermarket and got an 8 gig TDK USB pen for peanuts. I used the lion automatic application to make a boot up usb. I installed the following....

Intel 520 120 Gb SSD in my macbook pro and formatted it with disk utility. The SSD was instantly recognised and install worked flawlessly first time round.

I'm now enjoying a seriously fast and slick mountain lion. I have had ZERO issues. I'm happy to post xbench scores. Kind regards.
 
Everything is grayed out because for some reason you are booting from it. You can't erase a drive that is being booted from.

I'm booting from the USB Mountain Lion installer drive, not my SSD hard drive. :eek:
 
@klmaj

Sorry if this is a basic request but could you post a quick step by step guide as to how you partitioned your SSD and installed Mountain Lion?

I am making the exact same upgrade on my 2011 MBP. I already have a boot up USB for mountain lion - so could you make a quick post step by step guide as to how to partition the SSD before installation of ML and then the steps to install ML.

In case you can't tell, I'm a complete noob with this type of things so your help is greatly appreciated! :)
 
clean install ml on new ssd?

can I install a new ssd in my MacBook pro, put the original hd running lion in an enclosure, boot from that , then format and clean install mountain lion on the ssd I just installed in the Mac pro? there are so many threads, I'm trying to tie it all together.
 
haha. seems like we're all doing this lately.

I just did the same thing 2 days ago, Created a USB Boot drive via Disk Utility, and fresh installed Lion, then upgraded to Mountain Lion.
 
I used an "old" intel 40gb ssd to install mountain lion, booted from the ml USB installer, I can erase the ssd but the erase option is greyed out. Meaning I can not choose to zero out the drive, so I can only do a quick erase.

http://i48.tinypic.com/12663w9.jpg
What gives??
 
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