Hang on, hang on. Don't go booting other operating systems just yet. You said your connection was live and you were able to ping things. Do this:
ipconfig/all
How many adapters do you see now. You said you de-installed one earlier -- that was a mistake but not fatal. You should not expect to see two adapters connected.
The Ethernet Adapter/Local Area Connection should not be connected -- that's your ethernet card/port ... the RJ45 socket on the back of your laptop. Since you have nothing plugged into it, it is naturally not connected. Is that the one you deleted? Don't worry about it for the moment.
The other one is your Wireless Network Connection (which may also say Ethernet Adapter). You should see filled in values for IP Address, Subnet mask, Default Gateway (which will be the address of your router), DHCP Server (probably the same), and DNS servers.
Start by pinging the address of your default gateway, i.e. ping 87.198.24.1 or whatever the number is. If you get replies here you are connected wirelessly to your router. From what you said earlier, this is probably working. Check that it still is.
Now take the first DNS address that is listed. Ping that. That is set by your provider (Eircom) and will be the first "hop" outside your house. Do you get replies from that? If so you are definitely connected to the internet. If not, your problem is more local.
Lets assume you can ping your DNS. Now type this: nslookup
www.google.com
If your DNS is responding you'll see something like this:
C:\>nslookup
www.google.com
Server: somedns.eircom.net
Address: 172.16.164.xxx
Non-authoritative answer:
Name:
www.l.google.com
Addresses: 74.125.77.104, 74.125.77.147, 74.125.77.99, 74.125.77.103
Aliases:
www.google.com
If you get this far, take the first of those Addresses -- 77.125.77.104 above, and ping that. If you get reponses, your internet is 100% ok and the problem with your Browser connection is not your network. I think someone else already mentioned checking that you are set to *not* Work Offline.
If you are using Internet Explorer 6 or 7, go into the Tools menu, pick Options. Pick the Connections tab. Click the LAN Settings button at the bottom. What is the "automatically detect settings" checkbox set to? If it is off turn it on. Save your settings and quit Internet Explorer ( -- completely: make sure all windows are closed... it only detects settings on very initial startup). There may be a delay while the browser is starting up. When its responsive see if you can connect to Google.
Let me know how you get on.