Grey Screen, Spinning Wheel of Death

I've tried nearly everything, SMC, PRAM, Reinstall, run every report possible but I cannot login into my Mid 2009 MBP.

I have reinstalled Mavericks for the second time just now and it is hung on a grey screen.

I can boot up into OSX Utilities mode.

I cannot boot up into safe mode.

This all started with the appearance of the Spinning Wheel of Death and progressed to Grey Screens when rebooting.

At first I thought it was lack of disk space so I connected to my HDD in Target mode and cleared things up so I have 30gigs free.

How do I identify what the problem is so I can fix it?

I'm assuming you mean you can boot to "recovery mode" not utilities mode. While in recovery select Disk Utility from utilities and run a verify on your hard drive. It sounds like your hard drive may have problems. Have you been making backups? Let us know the results of the hard drive verify.

Hey thanks for your reply. Yes. The first thing I did was run the disk utility and it comes back with a Verified disk report.

I will shortly put OSX onto a memory stick and try and run off that. To see if we can narrow things down a bit.

I ran EtreCheck and got this....

Kernel Extensions:
/System/Library/Extensions
[not loaded] com.seagate.driver.PowSecDriverCore (5.2.4 - SDK 10.4) [Click for support]

/System/Library/Extensions/Seagate Storage Driver.kext/Contents/PlugIns
[not loaded] com.seagate.driver.PowSecLeafDriver_10_4 (5.2.4 - SDK 10.4) [Click for support]
[not loaded] com.seagate.driver.PowSecLeafDriver_10_5 (5.2.4 - SDK 10.5) [Click for support]
[not loaded] com.seagate.driver.SeagateDriveIcons (5.2.4 - SDK 10.4) [Click for support]

any thoughts?

More information is needed. Are you using an external Seagate hard drive and did you load software that came with the drive, perhaps for backup? The reason I ask is apparently a kernel extension (kext) was loaded for the Seagate but now you're getting errors that the driver is not loading.