Go back from what? I assume you mean Colemak? So you haven't got Colemak working on your work machine? And as such having to use Qwerty is prompting you to struggle with a hunt and peck style, and by going back to Qwerty you'll get faster?
How long have you been using Colemak and do you like it?
That would really frustrate me too, I wish OS manufacturers would make it trivial for users to swap their keyboard layouts, sharing a PC is not uncommon.
Under Linux you need root access to change the keyboard layout in the terminal. Apparently it's because it could be a way to screw with another user that comes to the machine after you. Fair enough, but why not make it really obvious which layout is selected, and make it really easy to swap...
Anway moan aside, seems your best bet would be a hardware option. I know some keyboard's have Dvorak as an option, independent of the OS. There may be a Colemak board about? Plugging in your own keyboard is probably less hassle than trying to seduce your network admin.
One pro of Qwerty is that it's an established layout. Straying from mainstream defaults can be problematic. Shame though. I chose Dvorak over Colemak simply because it was more widely available across platforms, but having said that you can still run into similar issues of having to have permission to swap layouts, and there is still some friction when sharing PCs.
--
Physicians deafen our ears with the Honorificabilitudinitatibus of their heavenly Panacaea, their sovereign Guiacum.