Mac blue screen with cursor on startup is really a frustrating situation as the the Mac will not boot. You will also not be able to access any of your files from the Mac drive. You might be looking for a way to resolve the Mac blue screen with cursor on startup issue somehow. Do not get worried as you will get here all the help you need for fixing the problem and to recover any data if lost. The error may be caused when the operating system is not getting loaded properly maybe there is something wrong with the start up disk. You can use the disk utility for detecting the problem in the start up disk and fixing it. If Mac blue screen with cursor on startup still shows up then you may have to reinstall the Mac OS X to solve any corruption issue of the registry files or the system files. You have to be cautious as you can also lose data from you Mac drive while fixing Mac blue screen with cursor on startup. You can recover the data if you have the backup or you have set up the time machine. If you do not have the backup then use the Mac data recovery software to restore all your lost files.