ok all net cafe has some kind of program like cafe agent or some net administration tool...(looks like a trojan)
This tool allow a computer that has the program-client to remote control another computer in a network... in our case usually lan(local area network)
first you must see how secure is this ok first go with Ctrl+alt+Del perhaps task manager will appear or some panel...
If you see task manager find the application that controls you and terminate it...
or log off...
If you log off you can see the username of the user that is currently running...
Ok now for more secure net cafe
Do a restart and press F8 continuously before windows boot...
you will go to a menu then select safe mode... and boot
now you are in...
you can copy the files c:/windows/repair/sam and c:/windows/repair/system on a disk
sam:holds the account passwords(encrypted)
system:has the key algorithm that is used to crack the hashes
then go to your home pc download a sam crack tool recomend(saminside) and crack the administrator password...
Go to the next cafe do some log off(by safe mode or Ctrl+alt+Del) and log in as admin change the pass and you got root...
Keep Learning...