Hi Sai,
Please check whether the following explanation helps you:
"Please create a service for your MIME service as per following SAP Note along
with the anonymous login user:
516884 - Anonymous logon with BW 3.0A/B and SAP Web App. Server
Please check if your anonymous mime service is active as per these
notes. Please also review the following SAP Notes:
653099 - Repeat password request when you download to Excel
735493 - Excel 2003: Logon screen with "Save as"
743839 - Export to Excel and the SAP logon screen
Effectively, we are aware of two typical situations that can cause
such a user+password popup.
(1) Newer Microsoft products query the web server with an OPTIONs
sequence once a document is loaded via the browser. Thus, Excel is
just asking the server if it supports additional actions. However,
Excel does not have, nor does it use the authentication information
from the browser. So the server does not answer this request, but
sends back a challenge for name+password (rc=401). User enters data,
Excel sends OPTION again, server answers no additional options
available.
(2) A variation of the above scheme is when the Excel document
references other templates from the server, and Excel wish to check
that they are still up to date."
Please note that these notes I mentioned here can be referred for Release 7.0 too.
Thanks & Regards,
Sapna