Win Media Player / Video Clip Blocked

[smartin22]

Hello-

When I try to load a vid clip on Mom's new Dell Dimension 8400 3.4 GHz, 1GB with Windows Media Player Ver 10, I receive the following two error messages, courtesy of Win XP SP2:

1. Windows has blocked this software becuase it cannot verify the publisher
Name: sg726acm.cab
Publisher: unknown publisher

I follow the help banner and:
IE->Tools->Internet->Content->Publisher
and try to import the video clip, but this doesn't work, apparently becuase the publisher / certificate aren't recognized.

2. An audio codec is needed to play this file. To determine if this codec is available to download from the Web, click Web Help.

NOTE: Problem occurs with .ASF files, but .AVI files seem to work fine. Suggestions for resolving these two errors would be appreciate since I am unable to watch the video clip on this computer.

Thx.

Scott