XP Home - Group Policy?

I'm working on cleaning up a PC running Windows XP Home edition. It was
loaded with adware/spyware & a few viruses. I used a variety of utilitys
and have apparently cleaned all of the stuff off. Now I'm having a problem
w/Windows Update not working. I was able to installed XPSP2 from an
installation CD. But, the firewall is disabled, at least in the security
center. But doing a netsh firewall show status, it says it's enabled. In
the security center, it says that there is a group policy in effect which
has disabled my ability to change the mode (i.e. on/off). But, XP home
doesn't support group policies, and doesn't come with gpedit.msc. I tried
coping gpedit.msc from an XP Pro system and using that, but it won't
initialize.

How can I reset the 'policy' settings which are interfering with the
firewall?

Thanks.

John