I keep a USB folder for family tech support. Zip-based search, duplicate finder, disk space viewer. Search gets used every visit — someone always saved it "somewhere."
Portable matters when you can't install on a machine you don't own. Unzip-and-run avoids admin prompts and registry leftovers.
What's on the stick
Filename search (64-bit zip). Process Explorer portable. Temp cleaner. All free, familiar UI so I'm not explaining from scratch at the kitchen table.
Check where the tool stores its index before running on a work laptop. IT notices mysterious index files sometimes.
Lite vs full portable
Some vendors ship lite builds without shell integrations — search without context menu hooks that trigger UAC. Delete the folder when done, gone.
See also: Finding files after a Windows reinstall, Small utilities that stay out of the way.