I'm not sure why you are erasing your TM backup. But to erase and reinstall:
Drive Preparation and Install of OS X
1. Boot from your OS X Installer Disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities menu.
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, set the partition scheme to GUID (for Intel Macs) or APM (for PPC Macs) then click on the OK button. Click on the Partition button and wait until the process has completed.
When formatting has completed quit DU and return to the installer. Complete the OS X installation.
After trying to restore my dock, I somehow slowed down, severely, my iMac response. I've booted up using the installation disk with the intent of restoring the iMac from Time Machine via Disk Utility. When I select erase, Disk Utility asks me to nominate a source. When I click on thetime machine drive, I get a file named macintosh.sparebundle. I select this. Then I need to select a destination (my hard drive is what I want). It tells me to drag the destination into the destniation field. This is where the trouble starts - it won't let me do this.
Is there any way I can wipe my iMac completely, reload the OS then restore everything from Time Machine?
Ok, your trying to erase your TimeMachine backup when your computer is on the fritz.
Not a good way to go about things.
If your Dock is on the fritz there is a way to fix it.
In your Library/Preferences folder is a file called
Delete this file in the Trash and reboot your machine. See how your Dock acts now.
If it's ok then your fine.
If you really want to restore from TimeMachine, you need to put up with the slow Dock until you have grabbed your files off to another external drive (not TimeMachine)
You next hold c and boot off the installer disk and select Disk Utility from the file menu and this time select your internal boot drive, not the TimeMachine drive.
Format the drive HFS+ Journaled and when it's finished Quit Disk Utility and your in the OS X installer, now install OS X on the internal drive.
Reboot and you'll go through the setup again and can restore from the TimeMachine drive.
If all screws up, at least you have a copy of your files on the second external drive.
com.apple.dock.plist does not exist.
Click on the Face Icon in the Dock to get a file window or
Click on the Desktop and when it says "Finder" up in the left corner Go File > New Window
Once you got that on the left is "Places" and under that is the name of your "user" account click that
In the window on the right should be a list of folders, one of those folder is called Library
DoubleClick on the Library folder and scroll down until you see the Preferences folder
Doubleclick on that and inside there is the
file, click and drag it to the Trash can and from the Finder menu > Empty Trash and click OK
Now reboot your machine.
What is an internal boot drive and where is it?
It's the internal storage where everything you have on the comptuer is stored.
When you hold c and boot off the installer disk, a couple of screens in there will be a menu option for the program called Disk Utility. You launch that and then select your drive on the left and click "Erase" and you chose a format, the defualt format is HFS+ Journaled which is what you want.
When you click OK, the disk is formatted and all data is eased.
When that's done you quit Disk Utility from the menu and you have a option to install OS X , you do that next.
Once that's all done you reboot the comptuer with TimeMachine hooked up and go through the setup like when you first got the computer.
Then it will ask you to restore from TimeMachine and you say Yes!
If you think you can't do this, take everything, your computer, the disk and the TimeMachine drive to someone who can or the Apple Store.