Error when trying to install Mountain Lion - says hard disk is damaged :(

Question

I downloaded and installed Mountain Lion on my iMac today - without any problems. But when I downloaded it to my Macbook pro (bought 2010) I get an error message telling me the installation cannot continue due to hard disk error My harddisk was fine before the installation, to my knowledge ...
Of course I tried disk utility (during the installation) and it tells me the disk needs to be repaired but I can´t choose "Repair disk" since it is grey (no write permissions it says). What can I do? I really need help!!!

Answer 1

I rarely post, however, because of a major screw up with Mountain Lion, I will.  I have been using mac computers since 1987, have obviously installed and upgraded multiple OS new and upgrades and never, I mean never had a problem with any of them, until now.  The install stalled with the message that the hard disk needed repair.  I thought all of my data was lost, except for time machine backup, which was not as current as it should have been.  Losing that data would have been a royal pain. 
Went through the restore OS from Time Machine, then tried to repair the disk with apple disk repair utility.  Not repairable.  Why?  I still don't have a clue.  After reading multiple threads, decided to go ahead and buy DiskWarrior.  This was a weird experienc.  Loaded it onto external hard drive, hooked my MacBook Pro as Target disk.  Loaded in DiskWarrior as hardware probelm.  ????  Immediately went online to see what advice about this message.  Looked like a massive coincidence had hit my laptop.  Worked perfectly until loading Mountain Lion, the decided to have hard disk melt down.  Suddenly, DiskWarrior indicated it was ready to rebuild my directory.  The hardware warning was gone.  A few minutes later, directory repaired.  Rebooted, same problem.  Can't load OS X, need to repair hard disk.  Apple disk repair still unable to repair disk.  Used DiskWarrior, repaired it no problem. 
Deleted original OS 10.8 dmg.  Rebooted and downloaded fresh copy of OS 10.8.  This time install went flawlessly.  Mountain Lion transferred all info flawlessly.  Mid 2009 MacBook Pro running flawlessly and actually more smoothly now than in Lion.
1.  I think original download was somehow corrupted and that is what screwed up the disk directory.
2.  I do not know why apple Disk Utility would not repair the disk and Disk Warrior would.  Expensive fix, but ultimately worthwhile.  Did it mysefl and did not have to mess with "Genius" bar.
3.  I will never go so long without backup again.  That was a big mistake.
My advice:
1.  Be sure you have smooth download of entire Mountain Lion file, if not, start over.  My download was paused a couple of times.
2.  If the install is messed up and you need Disk Repair, buy DiskWarrior and repair directory, it works flawlessly.  If it initially says your disk has hardware problem, wait a few minutes while it finishes entire evaluation.  It may well disappear like mine did, then actually repair the directories without a problem.
3.  Be sure you have deleted old OS 10.8 Install file and load fresh one.
4.  Install OS 10.8 and you should be OK.
5.  Good luck.
Mountain Lion seems to have some problems, but many of them may be due to server overload at apple, delayed download with incorporated unrecognized code problems.  If there is any delay, start over and get a smooth download.
Disk Utility is too light weight.  Apple needs to beef it up.  This is my biggest complaint.  Apple utility should be able to fix disks.  We should not have to spend $100 to fix a disk, but there you are.
Once fixed however, back to usual beautiful, flawless apple experience.