please somebody help me on my computer acting crazy

[indianhole]

my computer acting crazy maybe virus or something when i go to serach for something in yahoo or google site. when i search it and click the right site with in fewseconds take me to some to other site why it's happening.i installed avg and mcfee few days ago and doing same thing anybody know how to fix it.

[painter460]

http://www.malwarebytes.org/ download the free version and run the program

[Mavrick]

And run your scans in safe-mode if possible.