SAPRouter

Hi,

I have a fresh OS win 2003 system and I need to install SAProuter. I want to know, whether I have to Install SAP R/3 before installing SAProuter? Or I can create a new folder SAPROUTER and keep the saprouter.exe files in the fresh OS because in that system its not having usr/sap directory. Whether I need to create this dir also. What are the prerequisites for installing SAProuter. When I look into market place, I can able to find only the xxx.sar files not an installation files.

Thanks

Regards,

Ral