If I unconnect my negative terminal on my 2007 audi will it mess the computer up?

Nope.  You may have to reset your clock and radio settings and that is all.

Not at all. Just don't touch the two terminals together. Disconnect the negative then the positive.

Some vehicles will require a process to reboot the ECU if you disconnect the battery.

You can usually find them on youtube.

If you leave it disconnected long enough the computer will lose it's adaptive memory. That means it will have to relearn the idle speed and your driving habits which may effect the transmission shift points until relearned.

You mean disconnect - so much for the grammar nazi. No. Of course not. How else is one supposed to change a battery? About half the procedures in any auto repair manual start with "Disconnect the negative battery terminal".

I don't know. But unconnect isn't a word. The grammar fairy has spoken.