KB936929 disabled my PC

[Clamorous]

I was running Windows XP Media Center 2005 with AMD Athlon processor,
SP2 and all updates.

Last night when I got home from work I had the little shield telling
me that Microsoft updates were available. I installed the update,
KB936929. When it was done I got the message saying the update was
successful and ready to reboot. I let the PC reboot and it goes into
an infinite boot sequence. I get the black screen where I can select
what I wanted loaded, I let it default to Windows XP. I then get the
HP logo screen, then a black screen apologizing that the boot failed,
and if I've recently installed new drivers or software to uninstall
it. The boot process continues like this forever. After trying this a
few times I selected the option to boot from the last known good
session. This didn't change anything, still infinite boot sequence. I
tried to go into Safe Mode but got a black screen saying that <windows>
\system32\hal.dll is missing or corrupt, suggesting that I replace it.

I've been doing backups using Acronis to an external disk. I guess
I'll have to go this route to get the PC functional again. I've never
used Acronis to restore a disk, so I'm hopeful. My one question is:
should I do the restore during a full moon, or new moon.

 

[Donald Sessler]

I have the same operating system (Compaq Presario) and I tried to download
KB936929. After about 35 minutes I guess I was lucky and got an 0x80004005
installation failure. Solution said to try and install again. I did and
after about 5 minutes where no movement showed (no green bar) I cancelled
job. At some point I guess I will have to call MS as I'm a non techy.