Google wont search but can view other web sites

Hi, i'm in the process of fixing a mates laptop, the problems is:

When i open IE or Firefox i can goto google home page every time without any trouble, but when i try and sreach for anything it comes up as page cannot be displayed, if flushed the dns (ipconfig/flushdns) and it work for about 3 times, then does not load anything after that, ive checked for virus/spyware came back with a few so i cleaned them up, the only way i can contiune searching is if i close IE or firefox and flushdns and re open IE. ive had a search using another pc and cant really find anything, one last thing is msn is not connecting either not sure if thats connected or not.
Any help would be welcomed as its doin my head in :cry

Sorry if this is in the wrong section of the forum.

Cheers

 

well ive don some more digging and i hav now turn dns, this has made it more searchable with 19 out of 20 searchs resulting in sucsess,
i would stil like to know what the problem is rather than turning off dns client.
so any hlp would b hlpful ;-)