The easiest way will be to download a keyboard remapper to do the work for you. If you don't want to do that you can use the registry solution. SharpKeys Keyboard Remapper by Randyrants
Only attempt Registry Edits if you know what you are doing. Be sure to backup the registry first.
Open the Registry Editor
Start > Run > regedit
Navigate to: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout]
Select the Keyboard Layout Folder
Edit > New > Binary Value and name it "Scancode Map"
Double Click Scancode Map key and enter 00,00,00,00,00,00,00,00,02,00,00,00,2A,00,3A,00,00,00,00,00
As a value.
That will change the Caps Lock key into a Scroll Lock key.
Otherwise, you can download these registry tweaks which should do the trick for you.
Quote: Originally Posted by HowToGeek.com
Changes Caps Lock to be a Control key
Changes Caps Lock to be a Shift key
Disables Caps Lock and swaps Scroll lock to be Caps Lock
Disables Caps Lock
Uninstalls the preference by deleting the key