Must-have Windows software (installed)

I'm a strong proponent of portable software and avoid installing anything on my Windows computer.  So when I do, its something really important to have.

• PrimoPDF or PDF Creator - two programs that all you to print from any application and send the output to a PDF file.  Primo has more options but PDF Creator is open source.
• MyDefrag - Does optimized defragmenting based on daily, weekly, or monthly optimizations.
  
• TaskSwitchXP - although a newer and prettier version is out, I prefer this one because it uses FAR less memory.
  
• Google Calendar Sync - so I can check calendar events remotely.  The program only Syncs with Outlook, which is fine for me as my calendar software Rainlendar also connects to Outlook.
  
• Dropbox - backup your files and share them with friends very easily.  Also out for Mac.
  
• Flashfolder - an excellent program that keeps track of recently saved folders and posts a bar above any save dialog to give you more options to organize your files.  Awesome. Originally heard about this great program through freewaregenius
  
• Copernic Desktop Search - the only "desktop search" program among offerings from Google, Microsoft, and others.  Note that this program gradually losing ground to portable alternatives Everything and SearchMyFiles as well as the semi-portable DocFetcher
• Send To Toys - when you right-click on an item and choose "Send To" its nice to have some options you'll actually use and the ability to customize them.  Found via Lifehacker.