I was having this exact same problem. I used RegMon
<http://www.sysinternals.com/ntw2k/source/regmon.shtml to monitor what
was happening when I loaded a CSV. I noticed that it was attempting to
load the Quattro Pro converter. I deleted the reg key for this (in my
case it was
HKEY_CLASSES_ROOT\Installer\Components\3ADE92CC2CB 71D119A12000A9CE1A22A)
and there were no more errors.

I even reimported it to make sure that it was this that was causing the
error and the error came back.

Needless to say (but included for the anal retentive people), I deleted
it again and I haven't had any problems.

Brandan

Brian Schoner wrote:
I have just finished upgrading to Office XP, and when I
attempt to open a .csv file in Excel, I receive the
following error message:

"Microsoft Excel can't load the required converter.
Microsoft Excel can't install the necessary files due to
Windows Installer error 1605.
This action is only valid for products that are currently
installed."

After I OK this error message, the file opens normally.
Still, it'd be nice to avoid the message.

The message is identical whether I double-click the .csv
file to open it or I attempt to open it from within Excel.
I have re-run the setup program, and cannot find anywhere
to select individual conversion filters for Excel.
Researching error 1605 has turned up nothing relevant.

Any help would be appreciated. Thanks!

Best,

Brian Schoner