Hi Nexxus.

I've had the exact same problem.  I downloaded the image file and burned it
to a DVD and then tried to install from DVD - 1305 error message.

I installed a virtual DVD drive and tried to install directly from the image
file.  Same error.

I tried copying the files to the local machine to install it that way - Some
of the files didn't copy over due to some symbolic error that I think has to
do with the length of the file and file path.

I followed all the tips I could find on the web.  I turned off McAfee.  I
deleted all the files in the temp directory.  I turned off User Account
Control in Vista, all to no avail.

I tried to install on a PC with VISTA, and then tried installing on a
different PC using XP.  I re-downloaded the 2.3 gig file and repeated all of
the above steps.

After all this I still get the 1305 error message on the same file you
mentioned.  

It should not be this hard.  I fully intended to install the Professional
trial version as a bridge until I could order and recieve a full license from
an Internet vendor.  Now I think I'll keep the $800 bucks and wait until Orca
is released.

Prior to this fiasco I ordered VSTO 2005 and tried to install it on a VISTA
PC with Office 2007 (with the idea I would load and install the 2007 VSTO
update).  No can do.  You have to have 2003 office installed.  OK, so I tried
to install it on my XP PC that has 2003 office.  It still wouldn't install.  
After hours of research I found out I had the wrong version of 2003 Office
(the standard version).  

I hope someone responds who has the magic "workaround" but for the most
part, I've given up!  

Hi,

I had the same problem .. bit poor ... took a day to figure out!

I got round it by copying the whole VS directory to my hard disc and
replacing the corrupt file KB890803 with an exact same file downloaded from
Microsoft!!!

There's problems in the msdn direectory too but as it a 90 day trial I can't
be arsed!

Cheers
Phil