Help! Not Enough Quota is available to process this command!

[whitebloodcell]

I've inadavertedly let my Vista Activation period expire. SO turn on this morning, greeted with the options of running in limited mode, or turning it off. So I did the former. Firefox automatically opens up.

Managaed to get task manager running by typing c:\windows\system32\taskmgr.exe.

Then did New task, explorer.exe. Which worked, functionality restored, or so I thought. I'm trying to get cmd.exe open so I can rearm.

However, when trying to run cmd I am greeted with the message
"Not Enough Quota is available to process this command!"

So google that. Answer is apparently to free up some memory. So closed firefox, and hurray, cmd opens. then type slmgr - rearm. And hey presto
"Not Enough Quota is available to process this command!"

I've run out of things to shut down. So back to google, said to increase the page file size, so, Start, Control Panel....
"Not Enough Quota is available to process this command!"

What can I do? I CANNOT lose this installation.

UPDATE: Managed to get control panel open after closing firefox down however none of this options are visible.
UPDATE2: Closed down explorer after I opened cmd, which allowed me to run slmgr - rearm. Thought I had sorted it but then recieved the message
"Error OX800706BA occured in connecting to server. Error description: The RPC server is unavailable."

Thoughts?

UPDATE3: Once I got to the point where only cmd was open, tried "net start rpcss" and was given the same "Not enough quota" message.