virus and spam problem

my computer seems to be mad.I think it's been affecting by some virus or something like that.
my problem is : when my laptop is connecting to the internet and when i'm chatting with yahoo messenger the internet was disconnected automatically without my command.
also some strange programes or softwares was installed into my laptop automatically and don't even know why.
every time when i log on into my computer these softwares always coming up on the screen.
can anybody advise me the way to fix this or show me the website that i can download softwares to destroy these virus and spam once and for all.
thanks in advance for your help.

I'm not sure this type of question belongs in this section but anyway, it looks like you have spyware installed on your computer. These are usually installed when you visit certain websites or download stuff that have them attached. Your best bet is to download Ad-Aware. It's one of the best programs you can download to get rid of it. Of course it may not rid of everything completely but it's a start. You can download it for free here: http://www.lavasoft.com/ As for the virus problem, I'd buy a good virus protection program like Norton if you don't already have one. It's possible you do have a virus so you need to do a scan on it asap. Hope this helps and good luck!

thank you
i did try it the way you told me
my computer is much better
thanks again