Disable autorun for discs

                Put a disc in your CD/DVD drive and you'll notice an appreciable lag as it spins up, even if you're not just about to use it. If you don't always need your CDs and DVDs to launch automatically when you insert them, the needless spinning up of the discs can slow your machine down.

You can disable CD autorun by modifying this registry key:

'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdrom'. Double-click the 'AutoRun Dword' value and set it to '0'. Change it to '1' to restore it.