Setup: Fatal Error, Product Catalogs, Invalid Signature

[KC]

All,

I am working on my brother in-law's blaster infected
machine. He decided to disable RPC after checking his
event log and now it cannot be re-enabled. I have already
modified the reg key for the service to have it auto start
to no avail. The OS has limited functionality at this
point because of the RPC issue. I have no choice but to
back up his data and try to do a repair on XP Home. While
in the setup GUI I get the message that a fatal error has
occured: "setup failed to install the product catalogs.
This is a fatal error. The setup log files should contain
more information." The log file just repeats this message
and one other..."The signature for Windows XP Home Edition
Upgrade is invalid. The error code is 426".
I have googled and still nothing...checked the KB and have
not found any useful solutions. I have done shift-f10 and
renamed catroot. Didn't work. I have tried running the
setup from a diff drive..didn't work. I am basically
stuck in a setup loop. Any assistance GREATLY appreciated!
KC

 

[KC]

Bueller....Bueller....Bueller..?

Ok so i found ONE more potential fix for this issue and
that was posted on experts exchange. The suggestion was
to replace the DVD-ROM w/an older CD-ROM. That did not
work either. I'm @ your mercy.

 

[Craig]

I have the exact same problem. Still searching for the
answer when i found you post. Hope someone out there has
the answer.

Thanks in advance