I discovered I had ctfmona on my computer. A search led me here, where installing and using Combofix was suggested. I did that, and now I have nothing. My desktop picture and the taskbar w/Start, the clock, and icons for AVG and Windows firewall are there, but all desktop shortcuts are gone. While the start menu will pop up (reluctantly), 'My Documents' can't be found. 'Control Panel' results in a 'null' error message. 'Search' doesn't work. Actually, nothing normally found on the right side of the start menu will work. Cntrl+Alt+Delete does bring up the Task Manager; al the processes seem to be there. Performance shows a zig-zag up and down between 10-25%, with the PF usasge at 600mb (albost a full graph).
I also can not boot up in 'safe' mode. HijackThis can be started from the process page at C+A+D, but it doesn't show anything out of the ordinary, other than teo 'file missing' entries: 021 catdmgqt.dll and 023 rpcapd.ini

What can I do??

reinstall windows

I would love to, but although it's a valid copy, I have no disc, and thus, no idea.

some malware detects when its being removed by combofix and deletes the system

I'd be hard pressed to disagree with you, but what can I do to remedy this?

try going to run and typing sfc /scannow

you may need a windows cd. it doesnt have to be your one (borrow a friends if you need to), it just has to be the same version + service pack.

sfc will check for missing system files

Typing "sfc/scannow" into the 'run' box doesn't work. Did I leave something out?

I am pretty sure there needs to be a space between "sfc" and the "/"

yes, sorry

sfc /scannow

System restore to before you used combofix. Who instructed you to run it?