sap gui 7.10 installation

Hi there

I am installing sap gui 7.10 on a LT running XP. Sap installs fine. When I open outlook, I get a message box:

File download- security warning
Do you want to save this file
Name : mso??.tmp
type : unknown file name
from : outlook:today(outlook 2003 installed). On opening any e-mail I get
Can’t open this item, text formatting cmd is not available, plse install outlook. when I re-install outlook same problem.

PLSE HELP
THKS
DG