Hello, has anyone ever been able to install a service pack without an active subscription? SW2008, SP5

It has been a while since I've used SW and had to reload from my original disk SW 2008 SP 0, well I wanted to upgrade to SP 05, but it seems that I am unable to do it without an active subscription.  Does anyone have any ideas on how to do this without a subscription on an older product?  Thanks!

SolidworksGeneral