Usually, the Virus TI2 doesn't include installation disk within the box. Instead, you go and register you Virus TI on
Access Virus and for this you provide the serial number on the Virus TI you bought.
Make sure to register fast, because if the seller didn't asked Access to delete his registration, you'll have to write to your seller and to Access Support to help you. Hope you do all of this before providing feedback on eBay.
Once you get registered, you download the latest OS which is 4.5.3 (stable) or 5.0 (public beta)