I had a USB that I carried around with me with a whole bunch of portable apps on it. That allowed me to have some kind of "standard environment" I could rely on.

I've since migrated to Linux 100% (outside of work) and whilst there are the odd annoyances, it's been a breath of fresh air compared to Windows. And I can have a good chuckle almost once a week these days with each new Windows consumer hostility coming across the HN front page.

You can do that (probably even better) on linux with a Live Usb. I have a fedora one on my keychain since it has firefox and libreoffice included by default