Although Comodo does not own its own root, it uses the Baltimore Root.
It is a bit more compatible than GeoTrust's browswer. GeoTrust
doesn't support IE version IE 5.0 or earlier. Only Thawte or Verisign
supports those.
http://instantssl.com by Comodo is actually be better
than GeoTrust's certificate with respect to how many
different browser and versions support it. It will support
the IE 5.0 version, and Opera Web Browsers, but will
not support anything earlier than 5.0, just like GeoTrust.
http://www.whichssl.com/browser_recognition_table.html
IE Version Shipped With
--------------------------------------------------------------------------------
IE 1.0 comes with Win 95 PLUS pack (not part of Win95 by default)
IE 2.0 comes with Win NT4
IE 3.0 comes with Win 95 OSR2
IE 4.0 comes with Win 98
IE 5.0 comes with Win 98 SE and Win 2000
IE 5.5 Win Millennium Edition (ME)
IE 6.0 Win XP Home/Pro
If you friend does not want to pay alot, going with
http://instantssl.com at $49/yr is still a good idea.
I would rather still buy that than the $159 GeoTrust Cert.