In Internet Explorer, CTRL+ENTER is a very useful shortcut. It adds http://www. before the text in the address bar and .com at the end.
Example: If you want to visit http://www.microsoft.com all I have to do is type microsoft in the Address bar and then press CTRL+ENTER. To change what CTRL+ENTER does, see this excellent tip from Jeffdav's blog.
Example: You can
replace .com to .net
Create the following registry key:
Create the following registry value in the key above:
QuickComplete (REG_SZ) http://www.%s.net (Or, co.in, co.uk etc)
Whatever is in the address bar will be inserted where the '%s' is. This example would complete 'microsoft' to 'http://www.microsoft.whatever'.
Source: How do I change what CTRL+ENTER does in IE?