My MacBook Pro won't start - it just displays a grey screen with flashing icon of a folder with a question mark in the middle. Help.

Question

It started while I was using Adobe InDesign, and that program froze, then crashed. When I tried to reopen the program, the error message I received was simply "Error: 16".
I tried to take a screen shot of the error message for reference, and it gave me a message saying I couldn't because I didn't have access to the files where it would normally store the shot.
Attached to my computer at the time was my Seagate Free Agent Go-Flex for Mac backup drive.
So, I closed any open applications, and restarted my computer. But it wouldn't restart. It only displays a grey screen with a flashing icon in the middle of a folder with a question mark on it.
I have no idea what happened - I wasn't using the machine any differently than usual, and it only had a few basic applicaitons open in addition to InDesign (like Preview, Text Edit, Microsoft Word, iCal).
I have MacKeeper on my MacBook, and I keep it clean.
Does anyone out there know what this flashing icon indicates, and if there is anything I can try on my own to fix it?
Thanks.

Answer 1

ali har wrote:
It started while I was using Adobe InDesign, and that program froze, then crashed. When I tried to reopen the program, the error message I received was simply "Error: 16".
I tried to take a screen shot of the error message for reference, and it gave me a message saying I couldn't because I didn't have access to the files where it would normally store the shot.
For the Error: 16
http://kb2.adobe.com/cps/827/cpsid_82744.html
Seems a uninstall and reinstall of CS is in order.
Attached to my computer at the time was my Seagate Free Agent Go-Flex for Mac backup drive.
May or may not be a contributing factor,  may have kicked in at a wrong time or running root code.
So, I closed any open applications, and restarted my computer. But it wouldn't restart. It only displays a grey screen with a flashing icon in the middle of a folder with a question mark on it.
Computer can't find a bootable volume.
https://support.apple.com/kb/TS2570
I have MacKeeper on my MacBook, and I keep it clean.
Well that explains it, MacKeeper is almost malware.
http://applehelpwriter.com/2011/09/21/how-to-uninstall-mackeeper-malware/
Search the forums here for "MacKeeper" they will tell the whole story, crapware.
Disconnect all drives, follow the "Grey Screen" instructions and hold Shift key down while booting, if you get into OS X , immediatly backup your files to another drive and disconnect.
In my opinion you should first check to make sure you have a backup of your data, then just erase the entire internal drive (hold c boot off the 10.6 disk, use Disk Utility), reinstall OS X, same user name, update to 10.6.8, c boot off the 10.6 and Repair Disk (to fix a update error) install your programs and finally return files from backup into the same main user folders like before (Music, Docs, Pictures etc.)
A pain it is, but you've hosed your system and in the process you might as well rebuild everything and have a fast machine again. So happens to clear MacKrapper, uninstall CS5 and any other junk in your system at the same time. Fresh, clean, lean and mean.
Learn to Carbon Copy Cloner to a external drive that new pristine boot drive, you can hold the option key and boot from it (even update it), which is a real bacon saver when something like this happens.  Also it's free to use, donations accepted.
http://www.bombich.com/
Note: if anything above I've mentioned is too complicated or your not sure, seek the services of a local computer specialist.