that will make things worst. Rkill was developed to kill the malicious processes added by trojan and being use by rogue/fake AV such as Antivirus Soft.
Follow the steps in that guide you linked to get rid of Antivirus soft and other malware that caused that infection.
Does anybody know how to remove AntiVirus Soft from Windows XP? I found some theories on google but they all include downloading some random file to allow the virus to temporarily shut off and I dont want to download some virus or trojan etc. and make things worse.
Here is one example of what I found http://www.bleepingcomputer.com/virus-removal/remove-antivirus-soft
Does anyone have any advice?