Ah, good thread.
Here is a list of little programs I use to help working:
qttabbar >> Adds tabs to windows explorer, so you can (far more) easily have multiple folders open and browse through them.
inkscape >> Vector graphics drawing utility
bulkRenameUtility >> Rename multiple files at once with this. Want to add a date to 1000 results files? This is the way to do it.
pdfSAM >> Split And Merge pdfs - simple and effective.
Zotero >> Manage any reference libraries you may have - can act as both a search engine for them and also reference them in word/libre office.
AutoHotKey >> Have repetitive processes in windows? Macro them up with autoHotKey and save your brain from mind numbing repetitiveness... and also do things 10x quicker.