Have you been stuck on the iMac startup disk full message ? Whenever you power up your iMac you get the message and the system does not boot up. You are unable to get to the welcome screen or access any data in the iMac drive. You must have stored many important files that has become inaccessible due to this error so you will have to fix it. The cause of this error is generally too much of large files stored in the same volume where the Mac operating system files are saved. The Mac OS X file could not be retrieved at the startup and the imac startup disk full message is shown. You should try to clear up some space by removing the junk files through the disk utility program. However there is a possibility that some of the important files also get lost in the process. Now to get that use the time machine backup, but if it is not functional then you can use the Mac data recovery software that is completetly compatible with your iMac and the version of Mac OS X you are running on it. So you should scan the drive with it and when you get the list of files, select them for recovery. Download the software when the imac startup disk full message stops coming and get your data back.