how to block svchost.exe 255.255.255.255?

I have question, after format C: and re-install new windows xp SP3 PRO.

First, DISABLE "SSDP Discovery Service"

and, that, svchost.exe "generic host process" , 239.255.255.250:1900

I known goto "HKLM\Software\Microsoft\DirectplayNATHelp\DPNHUNNP\
UPnPMode , REG_DWORD = 2

But I not understand that svchost.exe "generic host process" "255.255.255.255HCP ",

how to block? is goto regedit to block?

If block "239.255.255.250" and "255.255.255.255 ", any future problems?

any advice please!

 

thanks, so far
goto "HKLM\Software\Microsoft\DirectplayNATHelp\DPNHUNNP\
UPnPMode , REG_DWORD = 2
block "239.255.255.250:1900" port, now I have no internet problems, is look fine,

but do you known what difference "239.255.255.250" and "255.255.255.255" ?
any advice please!

 

See this article and this article. I think these will answer your questions on the diffenence.