I once had a faulty cpu and windows denied booting. I was able to tell grub to load the kernel an run off of 3 instead of four cores.

I had that machine running another 2 years or so.

exactly.

gg -> go to top of document

d -> delete (actually, it's cut, but it destroys the mnemonic)

G -> here is a modifier to "d" and tells it do "delete until end of document"

w -> write current state of buffer to disk

q -> exit program