62. Disable DHCP with DSL connections

If you use a DSL modem to connect to the Internet, and you dial the connection directly from your computer, you may notice a rather long delay between the time the Windows desktop appears when booting up and when you can actually dial your connection. This delay can sometimes be up to two or three minutes, and can be extremely frustrating since it tends to lag other applications as well. The source of this delay is Windows XP attempting to locate an IP address for the network adaptor you are using to connect to the DSL modem.

This only occurs if the adaptor in question is set to 'obtain an IP address automatically' meaning Windows will actively seek to find an IP address for that adaptor from an outside source before assigning it one of its own range of addresses.

You can halt this behavior by simply assigning the network adaptor an IP address manually. It doesn't matter which IP address, as long as it is in one of the private address ranges (like 192.168.xxx.xxx). This will not effect your Internet connection, as the DSL modem and the adaptor form a separate 'virtual' connection which is assigned an IP address by your Internet service provider.

To assign your network card a manual (static) IP address:

Right click on 'my network places' in the start menu and hit 'properties.'

Highlight the network adaptor that is connected to your modem. If you have only one network adaptor, this will be 'local area connection.' Right click and select 'properties.'

Highlight Internet Protocol (TCP/IP) and click 'properties.'

Check 'use the following IP address' then in the 'IP address:' field, enter '192.168.5. (Pick a number between 1 and 254)' Enter '255.255.255.0' in the 'subnet mask:' field. Click 'ok.'

The next time you reboot, the delay should be gone, and you will be able to access your connection right away.

63. Do not cache failed DNS entries

By default, Windows XP will cache the IP addresses connected to DNS names (such as website addresses) as they are entered into your browser. This speeds up subsequent visits to the same addresses because the system does not have to search for the IP address that the DNS name represents.

This is good for Internet performance as a whole, but it does have a downside. If you type in a valid URL that is not functioning at that point in time, Windows will cache the unsuccessful result, meaning that all attempts to access that address may fail until the failed entry is gone from the cache. This takes about 5 minutes.
You can prevent Windows XP from caching unsuccessful DNS lookups by creating three new registry values.

To do this open REGEDIT and navigate to: 'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters'

Create the following DWORD values:

NegativeCacheTime= 0
NetFailureCacheTime= 0
NegativeSOACacheTime= 0

Reboot for the changes to take effect.