Getting rid of Virus attacks

My problem has to do with virus attack in my PC and I want your advice regarding how to get rid of those. I suspect it’s a sort of redirect virus and the problems started probably a few weeks ago. I will start with searching troubles I faced while using internet. Clicking on the search links I can sometimes find the correct pages but often the opposite happens. Very often search links ends up in ‘not available’ page. But I find the accurate site If I cut and past the link from the address bar into the search bar.
At times I identify fake sites and promptly go back to the previous page. As I re-try to enter the page, I can browse it. I am not sure whether I have succeeded to describe my problem but I am trying my best. My current operating system is Windows XP. For troubleshooting, I used AVG, Hitman, Malware Bytes and Kaspersky, but all went in vain. In addition to the prior problem, I get two error messages (attached to the post) when my Windows initiates.
I can’t find any connection between the messages. The viruses are giving me enough trouble and I need your help badly. Do I need to provide you with more information?
