No...it doesn't really require you to restart PC. But in order to take effect you need to restart your browser though.

Why it doesn't help? You just need to add one entry like this
127.0.0.1 forum.lowyat.net

then restart your browser
and walla, it is blocked! It does exactly what you want (according to the description)

If you're using router, you can make use of the powerful URL filtering feature (maybe some of the router use different names, but I assume the functionalities are more or less the same) to block some restricted websites.

Insist on third party software? Yes, firewall like ZoneAlarm can also help you to block websites. For anything else, just google for "website blocker" and there will be plenty of software for you to download (just to be careful that it doesn't contain spyware)

If you wanna do it in browser level, you can do what bobtiang suggested for IE, if you're using Firefox you can use adblock extension.

See? You're spoiled of choices, and I don't see why you can't achieve websites restriction

Play around with user accounts and access control. I'm sure you can do that.

Go to this folder
C:\WINDOWS\system32\drivers\etc

Open your HOSTS file with Notepad

Threads merged