Can i download free antivirus software onto a cd-rom and load it onto someone elses pc?

YES,

The law and most user agreements say that you can freely distribute copies of free software provided that you do not alter it in any way.

Can i download free antivirus software onto a cd-rom and load it onto someone elses pc?antivirus software

Yes.

Try some of these:

Spyware, Adware, Trojans, Malware, Dialers, Keyloggers, Popups:

http://www.download.com/Ad-Aware-SE-Pers...

http://www.ewido.net/en/download/

http://www.javacoolsoftware.com/spywareb...

http://www.download.com/Bazooka-Adware-a...

http://www.javacoolsoftware.com/sgdownlo...

http://www.safer-networking.org/

http://www.download.com/HijackThis/3000-...

http://www.emsisoft.com/en/software/down...

http://www.superantispyware.com/download...

Online Scanners:

http://www.webroot.com/consumer/products...

http://www3.ca.com/securityadvisor/virus...

http://www.pandasoftware.com/products/ac...

http://www.bitdefender.com/scan8/ie.html

http://www.windowsecurity.com/trojanscan...

http://www.kaspersky.com/virusscanner

http://www.spywareguide.com/onlinescan.p...

http://housecall65.trendmicro.com/

Spyware, Adware, Trojans, Malware, Dialers, Keyloggers, Popups Lists:

http://www.softpedia.com/catList/104

http://www.download.com/Adware-Spyware-R...