Can i have 2 types of anti virus software in my system?

Only one is needed. Having two leads to conflicts. Both of them would recommend not having more than one. Programs such as adaware (2007), and Spybot, would be a good idea, to compliment your system. Only one antivirus program tho!

edit.... to your additional details...

from the start button, goto Settings, then Control Pannel. Goto Add or Remove Programs. When the list is populated, find your expired antivirus, highlight and click "Change/Remove. That will uninstall. To install your new antivirus, simply load the CD and it should walk you through the steps to install.

~good luck

Can i have 2 types of anti virus software in my system?ducati

Yes you can. But it is certainly not advisable as they can compete with each other in terms of resources.

They also compete for the access to the security center api as released by microsoft and its the security center that gets confused.

not to mention the amount of memory that an antivirus requires

Can i have 2 types of anti virus software in my system?hp

Yes. They work independently.

My recommendation, though, would be to get something like AVG for main protection, then use Ad-Aware or Spyhunter to get the Spyware and other internet related items.
i would keep it simple ands use one good one. but thats me.
Yes, you can but they would suck up your resources and make your computer slower.
yes you can but having to anti virus or any type of security software does work however it can cause conflicts between the two in some cases and can lead to damage of files and even your hard drive so just stick to one i would recommend avg anti virus has the highest kill rate just now
yes