I think you mean CTRL + ALT (not ctrl + shift)
Just press CTRL + ALT + 1 (or 2, 3, 4, 5, 6, 7, 8, + or - )
I agree, this sucks, massively. This should be the new number 1 problem to fix for MS.
Anyone running a beta OS on all of their machines is asking for trouble (remember the weird mp3 deletion thing, was it Windows 7?). Sure, run a test box or two, but to migrate fully this early on...
Can't you lot on Verizon just take the sim card out and update over 'Preview for Developers' over WiFi? Not sure how it works in the USA, but in the UK the Preview for Developers app seems to...
I am going to attempt a dual boot or maybe a VM on my Surface Pro 3 with the Win10 Tech Preview... Paul, would be good to know if you have any success doing either too.