Huge usage showing but low use made

[#1]

More specifically a trojan (others may also cause similar problems) could cause all sorts of trouble.
Please run a virus scan (if not already done), installing NetWorx is an excellent suggestion (other software available but this one works and is free), you'll then know what traffic volume is going in/out from your PC, most (not all, unfortunately) routers also have at least a basic traffic volume monitoring function, worth having a look in the router interface.

[#2]

Virus scan runs permanently.
Today's usage is c.550Mb - for half a day so still too high.
However, in the last 5 hours usage has not been racking up the way it was yesterday. Good but very odd.
I still find it extremely odd that there was c.3Mb of usage BEFORE I turned this PC on and nothing else was on bar an internet radio for a few minutes.

Networx - btw, is this the software, at £25 a throw:- http://landwebmonnet.gfi.com/internet-access-control-sm/?adv=2106&loc=144&gclid=CMPgx8uHvrMCFXDLtAod... because that's where their website takes me.

[#3]

http://www.softperfect.com/download/freeware/networx_setup.exe

[#4]

Thanks, w23.
Usage has settled back to normal since the spike so no idea what went wrong.
Thx to all who chipped in.