How single is my single user licence?

[Patabugen]

I've just bought my licence =D I've got a single user licence
Does it mean I can only enter the code on one PC, one installation or only I can use software registered with the code?

I ask because I use FlashFXP on 3 different computers, and sometimes at other peoples places. If I install FlashFXP onto my USB Pen drive and register it will that then be useable whereever I take it?

Or for example if I install it on a network location am can I use it on different computers on the network?

Again, I'm the only person who uses it.