1. Initial problems getting usb drive with Mint 17.1 to boot. .
2. Also problems with Chromium browser and YouTube.
1. Eventually found the answer somewhere totally obscure online (press Tab key, type 'list', press enter).
2. Solved by downloading pepperflash and ubuntu restricted extras.
1 above drove me nuts - yet so simple in the end! This workaround should be made known somewhere obvious. Apparently, the problem is common with desktop installations.