Lion - applications constantly crash - any answers?

Question

Hi,  My MBP I bought in March 2011 with SL.  I have installed Lion but when using it applications regularly crash.  Excel, Word, Powerpoint, Adobe, safari, Mail, Outlook etc etc regularly stop responding and the crash/error reports send their message off to Apple or microsoft or whoever. 
So, I think I ought to wipe the disk clean and start again, maybe reinstall snow leopard.  I donlt have a time machine backup, but I have saved all docuemnts, photos, music, movies etc to an external hard drive.     
Are there any simple instructions on how to wipe the disk and start again.  
PS I have Lion operating on my iMac and it works just fine, never crashes or hangs - it's only a problem on the MBP.
Thanks for any suggestions
Bill

Answer 1

Perhaps you have applications on the MBP that require updating. Or you have third-party software installed on the MBP that's not installed on your iMac. Or you need to reinstall Lion. I would do this before wiping the drive and starting over. Also, try each of these independently:
Boot into Safe Mode and operate to see if anything changes.
Create a new user account, then log into the new account and see if anything changes.
Reinstalling Lion Without the Installer:
Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alterhatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.
When the recovery menu appears select Disk Utility. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list.  In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive.  If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the main menu.
Reinstall Lion: Select Reinstall Lion and click on the Continue button.
Note: You can also re-download the Lion installer by opening the App Store application. Hold down the OPTION key and click on the Purchases icon in the toolbar. You should now see an active Install button to the right of your Lion purchase entry. There are situations in which this will not work. For example, if you are already booted into the Lion you originally purchased with your Apple ID or if an instance of the Lion installer is located anywhere on your computer.