Is it alright to replace my Full Version BitDefender Anti-Virus 2010 with AVG Anti-Virus Free Edition 2011?

-Hello!.



I have a full version BitDefender Anti-Virues 2010, which I can't update to 2011 because I have to buy their 2011 version. But it's expiration date is 13309 days (36 years).



AVG Anti-Virus Free Edition 2011 is the most downloaded software in Download.com and has more than a hundred million users. (That's what I read)



So I was thinking of replacing my BitDefender Anti-Virus 2010 with AVG Anti-Virus Free Edition 2011, but I have doubts.



If I uninstall BitDefender; it's full-version's expiration date of 13309 days will be with it and I cannot take that back. It is a disappointment if it were to just disappear. It is a full version.



But every time my anti-virus (BitDefender 2010) scans, I feel outdated. Because it is very slow. Last scan took 3 hours. Three Hours. Though, it is a full version and it is a full system scan too.



I can't install more than one anti-virus because that will drastically slow my computer and horribly mess up with my files. Especially the ones I add in "exceptions". I only need one.



I need your help, to choose!full system scan take a lot of time but donot replace ur anti virus bitdefender is no.1 antivirus for some people n avg free antivirus is not so good because its a free edition so donot do it

if u liked plz rate best

yeah avast is good