AppleJack is a really handy troubleshooting utility for Mac that works even if you can’t load the Mac OS X GUI. Running in Single User Mode, it’s a simple menu-based tool to run a series of tests and repairs on the Mac OS. With AppleJack you can easily:

* Repair Disk
* Repair Disk Permissions
* Validate System Preference files
* Clear Caches
* Clear Swap Files

These are common Mac troubleshooting techniques, and really make AppleJack a handy utility in any Mac users toolkit. To use AppleJack, all you need to do is restart your Mac in Single User Mode by holding down Command+S during system start, then type applejack at the prompt. You’ll then be brought to the same menu you see in the screenshot above, where you can perform the necessary actions to get your Mac back in good health.

AppleJack is open source and free to download, highly recommended.

if Safari has crashed in the midst of browsing the web, you can restore your last session and all its windows, tabs, and URL’s just by:

• Go to the History menu
• Scroll down to “Reopen All Windows from Last Session”

This has saved me all sorts of stress and headaches when Safari crashes with important tabs open. Try it out the next time you have browser failure.

When facing a system crash or startup up problems on Windows Computers, troubleshooting the problem can be difficult to resolve. The first step with recovery is to use Windows Safe Mode option during startup. One Safe Mode option that will help troubleshoot boot problems is to enable Boot Logging which will create a log and help identify the device or driver that is causing the problem during startup.

When Boot Logging is enable, Windows boots normally, until the device or driver that is causing the problem either crashes the system or completes starting up but causes an error message in the Event Log. While booting, Windows creates a log file that lists every step processed that is attempted and completed.

You can then reboot in to Safe Mode and review the log file named ntbootlog.txt. The log is stored in the %SYSTEMROOT% directory (normally C:\Windows or C:\WINNT folder). Below is an example of ntbootlog.txt log file on Windows XP (Vista log is similar):

Service Pack 2 5  4 2007 10:45:44.500
Loaded driver \WINDOWS\system32\ntkrnlpa.exe
Loaded driver \WINDOWS\system32\hal.dll
Loaded driver \WINDOWS\system32\KDCOM.DLL
Loaded driver \WINDOWS\system32\BOOTVID.dll
Loaded driver ACPI.sys
Loaded driver \WINDOWS\System32\DRIVERS\WMILIB.SYS
Loaded driver pci.sys
Loaded driver isapnp.sys
Loaded driver compbatt.sys
Loaded driver \WINDOWS\System32\DRIVERS\BATTC.SYS
Loaded driver intelide.sys
Loaded driver \WINDOWS\System32\DRIVERS\PCIIDEX.SYS
Loaded driver MountMgr.sys
Loaded driver ftdisk.sys
Loaded driver dmload.sys
Loaded driver dmio.sys
Loaded driver PartMgr.sys
Loaded driver VolSnap.sys
Loaded driver atapi.sys
Loaded driver vmscsi.sys
Loaded driver \WINDOWS\System32\DRIVERS\SCSIPORT.SYS
Loaded driver disk.sys
Loaded driver \WINDOWS\System32\DRIVERS\CLASSPNP.SYS
Loaded driver fltmgr.sys
Loaded driver sr.sys

To enable Boot Logging on Windows XP and Vista, boot your Computer, and during startup continually press F8 until the menu screen appears:

NOTE: screen shot is from XP. Vista menu will look slightly different than XP.

Press F8 to display the Advanced Menu screen and select Enable Boot Logging

You will be returned to the menu screen and you should see Enable Boot Logging in blue displayed at the bottom of the screen (don't worry if this screen is not displayed and Windows starts to boot):

If the problem does not cause Windows to crash, and after startup has completed, you can review the ntbootlog.txt file. Look for any signs of problems loading device drivers. If you find problems, go into Device Manager and disable the device or uninstall the program, then reboot again. If the problem does not occur then you know it was that device and you should check the vendor website for new drivers or known issues.

If your problem does cause Windows to crash, reboot into Safe mode by selecting Safe Mode from the Advanced Menu screen. When reviewing ntbootlog.txt file, look for events that were attempted to load but not completed. More than likely the problem will be toward the end of the file (since that was the last item logged before crashing). When you identify the problem, either uninstall the application or go in to Device Manager and disable the device. Reboot your Computer and see if the problem still exist. If it boots without crashing, check the vendor website for new drivers or known issues.

If you are still having problems, enable Boot Logging again to see if new events are logged after you have disabled the device or uninstalled the program. If you are unable to fix the problem, you may need to have a Computer shop troubleshoot the problem for you.

Notes on Boot Logging:

• Boot Logging can only be enabled from Safe Mode. Once it is enabled, it only logs during the current boot. It will not log during the next reboot unless you enable it again from Safe Mode.
• If an existing ntbootlog.txt files exist, the next time Boot Logging is enabled, Windows will append to the existing log file.
• It is a good idea to have Windows create a new log when there are no problems or after you have added new devices. This will allow full logging to occur and will let you compare with a log when problems exists.

If Disk Utility reports any other issues that cannot be corrected, backup essential data, then perform an Erase and Install.

4) Read the Introduction screen, then click Continue.

5) If a dialog appears, type your admin password, then click OK.

6) In the Migration Method screen, select “From another Mac,” then click Continue.

7) If you are transferring via FireWire, connect a FireWire cable between your new Mac and your earlier Mac, then click Continue (skip step 8).

8) If you are transferring via a wired (Ethernet) or wireless network:

1. Make sure both computers are on the same local network, or connect them directly to each other with an Ethernet cable if both have an Ethernet port.
2. On the computer you are transferring files to, click "Use Network", then click Continue, then click "From another Mac".
3. On the Mac you are transferring from, open Migration Assistant, click "Use Network", then click Continue, then click "To another Mac".
4. Follow the onscreen instructions to connect the computers via a passcode and transfer files.

9) Select the hard disk and user accounts from which you want to transfer, and select whether you want to transfer applications, files and folders, or your Library folder.

10) Select whether you want to transfer your network, time zone, and Sharing settings, and then click Transfer.

11) When Migration Assistant is finished transferring files, click Quit.

If you back up multiple disks attached to your Mac, such as external hard disks or additional internal hard disks, and you want to restore data from one of these disks but it is not connected to your Mac (or the disk is no longer working), follow these steps:

1) Click the Time Machine icon in the Dock, or choose Enter Time Machine from the Time Machine menu extra.

2) Click the computer name found at the top of the devices group in your Finder sidebar, or press Shift-Command-C.

3) Click on the name of the unavailable or absent volume.

4) Select the data you want to restore.

5) Click "Restore".

6) When "The enclosing folders for some items no longer exist in their original locations..." dialog appears, click the "Choose Location..." button.

7) Navigate to the location that you would like to restore your data to, then click "Choose".

For this process, you should leave your computer in the same room as the Time Capsules, or use one Ethernet cable to connect your Mac to the Ethernet port on the existing Time Capsule, then use another Ethernet cable to connect from the existing Time Capsule to the new Time Capsule.

1) Configure your Time Capsule for your network. See the documentation that came with your Time Capsule for information about setting it up on your network.

2) Open Time Machine preferences in System Preferences.

3) Slide the Time Machine switch to Off.

4) Mount both Time Capsules on your Mac and open a Finder window for each of them by double clicking on each one.  Take note of the free space available on your new Time Capsule.

5) Drag your backup disk image from the current Time Capsule to the new Time Capsule.  This can take some time to complete because your entire backup will be copied.

6) Open Disk Utility (in /Applications/Utilities).

7) Drag the backup disk image from your new Time Capsule to the Disk Utility window.  Once completed, the disk image will appear in the device pane on the left of Disk Utility.

8) Highlight the disk image in Disk Utility and click "Resize Image" on the toolbar.

9) In the "New Size:" field enter the amount that equals the free space of the new Time Capsule you noted from above, then click Resize.

10) Double-click your backup sparse bundle in Disk Utility to mount it.

11) Click the "Partition" tab.

12) Drag the partition size divider down to the bottom of the "Volume Scheme" (to make it larger).

13) Click Apply, then click Partition. This will expand the size of your backup sparse bundle.
Tip: You can use Disk Utility to check the integrity of the backup sparse bundle: highlight the backup sparse bundle, then click the First Aid tab.  Click "Verify Disk" to check the sparse bundle.

14) Go to Time Machine System Preferences.

15) Click "Select Disk...", then select your new Time Capsule.

16) Perform a Time Machine backup.

17) After the back up, you can remove the Ethernet cables if desired and configure your wireless network to your liking.

If you upgrade to a new hard drive with a larger capacity, you may want to transfer your existing Time Machine backups to it before using it for regular backups.  To keep your existing backups on your new, larger backup hard drive, follow these steps:

1) Connect your new hard drive.

2) In Disk Utility, make sure it has a GUID partition and is formatted as Mac OS Extended (Journaled).  If needed, reformat the drive as Mac OS Extended with a GUID partition.

3) Select the new drive's icon on the desktop and choose Get Info from the File menu.

4) Make sure "Ignore ownership on this volume" is not enabled.

5) Open Time Machine preferences in System Preferences.

6) Slide the Time Machine switch to Off.

7) In Finder, double-click the current backup hard drive to open its Finder window.

8) Drag the folder "Backups.backupd" to the new hard drive.

9) Enter an administrator user name and password, then click OK to start the copying process.  This may take some time to complete because all your backups will be copied..

10) In Time Machine System Preferences click "Select Disk…"

11) Select your new hard drive, then click "Use for Backup."

Now, on your new hard drive, you will have all of your existing backups from the previous backup hard drive plus have more room for more new backups.