Is 'google.co.uk' down (unavailable) to everyone or is it a problem with my computer? Has my own website been 'down' during the last month?

When go to a web page and you get the "Server Not Found" error it could be that the page is 'broken' (their problem) or it could be a problem at your end. How do you know which it is? I'm going to assume that you've entered the correct address!
Go to: downforeveryoneorjustme.com and enter the address and it will tell you. Simples!

If you have your own website you will want to know if the site has ever been 'down'. Whenever the site is down you are potentially losing money! I use JoomlaMonitor for the sites that I am responsible for. I get a monthly report showing uptime; downtime and outage. This helps me to monitor the quality of the hosting company I use. For the record, I've had no downtime on any of my sites for the 12 months I've been receiving reports.
This is FREE for single sites.

Internet & Web