This error is making me so crazy… my localhost works fine until I installed nod32 v3 in windows vista business. But it works fine with windows xp… I’ve been searching the web for solutions but seems like none of it works for me.
Some solutions I gathered, it works for some but i’d still be looking for other solutions since these things listed below didn’t work for me.
SOLUTION 1
To access your hosts file go to.
1. C:(or Windows Folder)\\Windows\System32\drivers\etc
2. Open the HOSTS file using Notepad or any HTML Editor.
3. Look and delete :. localhost or :. 127.0.0.1
4. Save the file as hosts
5. Open your browser type localhost — it should work.
*I’m using Windows Vista Home Basic, Xampplite and Nod32 v3.0
Disclaimer:
If something happens on your computer don’t blame me. 
SOLUTION 2
Go to the Setup tab and click “Enter entire advanced setup treeâ€
Click “Web access protection†and uncheck the checkbox labeled “Enable web access protectionâ€
This worked using Vista Business SP1 and VS2008 SP1
source:Â http://www.donalyza.com/localhost-doesnt-work-in-windows-vista-using-nod32-v30/#comment-458
… and oh btw, some says their issue was fixed by using solution 1, but I don’t want that solution, I want some solutions that don’t need to modify my windows settings since this is a nod32 issue. I wanted something that needs to change on nod32 settings. I’ve tried solution 2 but it didn’t work out for me.
Looking for some other suggestions…
ESET Nod32 Update Keys