By registering or entering Twitter it doesn't give you any viruses ,but you should be careful not to click on any "phishing" or misleading links, such as random advertisements or other links that looks weird to you.
Any website can cause a virus to be placed in your computer. I highly doubt it, but twitter could have given you a virus.
Speekonia does not give your computer a virus and it is designed in a way that will not give your computer any malware.
Yes. It has some downloads to it that will give a virus to your computer.
No, World of Warcraft will not give your computer a virus.
No, Zune will not give your computer a virus.
no, they won't give you virus
Probably.
No.
No.
No
Microsoft voices do not give your computer a virus but make sure not to open other apps that may crash your computer.
It is very unlikely you would get a virus from there.