[How To] Revert to an older kernel

[~pcwiz]

[How-To] Revert to an older kernel

 

If your current kernel is unstable on your PC, heres a way to revert to an older version of the kernel. Note: Most of you guys already know how to do this. This is for the n00bs.

 

To do this, your PC has to be able to boot OS X in some way. If it can't boot, then try booting your drive using a VMware Virtual Machine just for the kernel replacement process.

1: Kernel Versions

 

You first have to choose a version for the kernel. The kernels currently in use are:

 

8.8.1 (OS X 10.4.8)

8.9.1 (OS X 10.4.9)

8.10.1 (OS X 10.4.10)

8.10.3 (OS X 10.4.10)

 

In my experiences, 8.8.1 is the most stable. The rule you should follow is, revert to a kernel 1 version older than your current kernel and keep moving back if the system is still unstable.

2: Obtaining a kernel and System.kext

 

You must first obtain a copy of the mach_kernel file for your version and a System.kext file that matches the version of the kernel. You can get the mach_kernel file from the root of an install DVD that matches the version of kernel you need (See listings above). The System.kext file is a bit harder to find. It is located in /System/Installation/Packages/ of the install DVD in one of the packages. You can open the packages using Pacifist (Freeware) to extract the System.kext file. Right-click the System.kext file and click Get Info and make sure that the version number matches the version number of your kernel that you are going to revert to.

 

Obtain the mach_kernel and System.kext files and place them on your Desktop.

 

3: Commands to type

 

Open the Terminal program (Applications/Utilities/). Type the following commands, pressing enter after each one:

Note: After entering sudo -s, enter your Administrator password when prompted

 

sudo -s

cp /mach_kernel /mach_kernel.backup

cp -R /System/Library/Extensions/System.kext /Backups/

cp -R ~/Desktop/mach_kernel /mach_kernel

cp -R ~/Desktop/System.kext /System/Library/Extensions/

 

4: Post Replacement

 

Open Disk Utility (Applications/Utilties). Choose your Mac OS X Drive from the left panel. Clcik Repair Permissions.

 

Cross your fingers and reboot!