Hi,
I am using wireless internet connection.Am not being able to access any website.The error says:
Internet Explorer could not find the search page.
It is strange as I am being able to connect to gtalk from my system.
Also sometimes I can connect to some websites for a minute or so.
Please advise.

You are more than likely experiencing what is called noise on your wireless connection.
Make sure your wireless router is away from anything that might cause this interference such as radios/stereos, speakers (the big magnet inside you know), keep it out of the corner, away from land line cordless telephones, cell phones etc... even a fish tank can cause this. So put it out in the open I have mine on the top of my book case. If you don't have a wireless router and are using WiFi signals around your home, make sure you aren't trying to a WEP or WPA secured network. If that is not the case a high-gain antenna or tweaking your antennas at the back of your computer can help. I think I convered all the areas of wireless... hope this helps.

Well I think the problem is because of the MCAFEE anti virus on my system.I think it is prohibiting the sites from being accessed.
When I disable the anti virus I get to access the websites.
Please advise.
I guess it is to do with some setting on MCAFEE

I am thinking that you might have the "options" or "preferences" set to filter anything out that has any type of tracking cookie... Which are typical for most web pages.
These cookies aren't harmful in a way that they are taking credit card information or anything like that... they just track if you have visited the site before etc. So first of all... You need to check your internet options panel and see if what you have as far as cookies enabled. Is it on the highest and not letting anything through?
Click on Start, Control Panel, Network and Internet Connections, Internet Options, then choose the Security tab, in the middle area what is your security level? It should be on medium.
Now with McAfee... (unfortunately... I don't personally like McAfee, it's a memory hog and too many obstacles for personal use. My Mom has it and I am taking it off her computer in August when it expires and put on either Panda or AVG Free. So much better programs and not memory hogs. With that being said, what I would first do is go step by step through your "options" area in McAfee and look for the item or items that is blocking all sites and uncheck it or what have you. That is all I can tell you right now about the McAfee, or I can give the advice of removing it from your computer and get AVG... WAY better! I can give you further instructions in about a week when I return home and shuffle myself to my parents... Can give you step by step then. I would try the two things I suggested though. Internet options, and look through options on McAfee.