Cannot install printer, because Print Spooler service does not work.

When trying to add a printer you receive error message:
"Operation could not be completed. The Print Spooler service is not running"

Start->Run (Win+R)
type: services.msc
in the list find Print Spooler service, check for Startup Type (should be automatic) right click and choose Start.
If the service starts successfully you can try adding printer again.

If after a short time you receive error message similar to this:
"Spooler subsystem app has encountered a problem and needs to close.

Download FixPrintSpooler.msi from Microsoft, run it and follow the instructions.

More info here: http://support.microsoft.com/kb/324757

Cannot add Outlook Data File - Maximum file size exceeded.

If you're trying to add .pst data file to your outlook profile and get the following error
"The file "drive:/path_to_your_.pst/outlook.pst" has reached its maximum size. To reduce
the amount of data in the file, select some items that you no longer need and
then permanently delete them by pressing SHIFT + DELETE".

Obviously you can not delete any messages because you can't add the data file itself. This case should be only for Outlook 2003 without sp2 because it limits .pst file size to somewhat 2GB, however I encountered a situation where this message was generated by Outlook 2007.

Fastest workaround for this is to share the .pst file and add it to outlook 2007 on another computer in you local area network and delete some messages to lower the size of .pst file. That is if you have a network and another PC with outlook installed.

The other way is to download microsoft tool for shrinking .pst files, then fix the file with SCANPST.EXE ) (if you have outlook 2007 it will be located in "drive:\Program Files\Microsoft Office\OFFICE12") and then try adding the Data File again.

Cannot start Microsoft Office Outlook. Cannot open the Outlook window.

When launching Microsoft Outlook 2007 you get the following error message:
"Cannot start Microsoft Office Outlook. Cannot open the Outlook window."

This might help:
Start->Run (or Win+R)
then type the following: Outlook.exe /resetnavpane

If this does not fix your problem, you can always try System Restore.