Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM

Insert the Windows XP startup disk into the floppy disk drive, or insert the Windows XP CD-ROM into the CD-ROM drive, and then restart the computer.
At the Recovery Console command prompt, type the following lines, pressing ENTER after you type each line:

md tmp
copy c:\windows\system32\config\system c:\windows\tmp\system.bak
copy c:\windows\system32\config\software c:\windows\tmp\software.bak
copy c:\windows\system32\config\sam c:\windows\tmp\sam.bak
copy c:\windows\system32\config\security c:\windows\tmp\security.bak
copy c:\windows\system32\config\default c:\windows\tmp\default.bak

delete c:\windows\system32\config\system
delete c:\windows\system32\config\software
delete c:\windows\system32\config\sam
delete c:\windows\system32\config\security
delete c:\windows\system32\config\default

copy c:\windows\repair\system c:\windows\system32\config\system
copy c:\windows\repair\software c:\windows\system32\config\software
copy c:\windows\repair\sam c:\windows\system32\config\sam
copy c:\windows\repair\security c:\windows\system32\config\security
copy c:\windows\repair\default c:\windows\system32\config\default

Type exit to quit Recovery Console. Your computer will restart.

http://support.microsoft.com/kb/307545/en-us

Error message that you receive when you restart a Windows XP-based computer: "lsass.exe unable to locate component"

To resolve this problem, follow these steps:

1. Insert the Windows XP disk in the CD drive or DVD drive on the computer. Press and hold down the SHIFT key as you insert the disk to prevent the Windows XP installation from automatically starting.
2. Click Start, click Run, type the following command, and then click OK:
   expand CD drive:\i386\ntdsapi.dl_ %SystemRoot%\windows\system32\ntdsapi.dll
3. Click Start, click Run, type cmd, and then click OK.
4. At the command prompt, type the following command, and then press ENTER: xcopy c:\windows\servicepackfiles\i386\ntdsapi.dll c:\windows\system32

http://support.microsoft.com/kb/922371/en-us

PST Repair for Outlook 2003/2007

PST repair in Outlook 2003.
The PST repair tool can be found on C:\Program Files\Common Files\system\MSMAPI\1003\
This tool is used if the pst file is corrupted or to fix a pst file size after deleting emails from your outlook. Sometimes even after deleting files/ email from your outlook the size of the pst stay the same. So in that case run the scanpst.exe tool and scan the pst files.

Change the temporary folder for Outlook 2003, which is used to save attachments

Outlook 2003 If you are using Outlook 2003, follow these steps: Create a folder under your profile and name it temp, then change the registry settings for Outlook to point the temp files to this folder Click Start, click Run, type regedit, and then click OK. Locate and then click the following registry key: HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Security\ In the right pane, double-click OutlookSecureTempFolder. In the Value Data field, type C:\users\username\temp\ and then click OK. Exit Registry Editor, restart the computer. http://support.microsoft.com/kb/305982