Windows 2008 is designed to fully support IPv6 and has IPv6 enabled by default. However, most users never need it. You may find that after each update or change of network configuration IPv6 is rebound on your adapter, even if you haven’t asked for it be. To correctly disable IPv6 follow these steps:
1. Click Start, type regedit in the Start Search box, and then click regedit.exe in the Programs list.
2. In the Registry Editor, locate and then click the following registry subkey:
3. Double-click DisabledComponents to modify the DisabledComponents entry. Note If the DisabledComponents entry is unavailable, you must create it. To do this, follow these steps (Usually SBS has this in already. Many standard Server 2008 installations may not already have this entry):
a.In the Edit menu, point to New, and then click DWORD (32-bit) Value.
b. Type DisabledComponents, and then press ENTER.
c. Double-click DisabledComponents.
5. Enter "ffffffff" (eight f’s), and then click OK:
Exit the registry editor - and reboot the computer.