Solution : https://service.sap.com/sap/support/notes/537066 (SAP Service marketplace login required)
Key words :
//sapserv3/general/frontend/sapgui/sapsetup/updates/620/, msi-package <path>\systemupdate, windows installer reason, exe form microsoft, installing sap gui, local security handling, update yourinstallation server, local system account, microsoft files listed, addthe property allusers
Related Notes :
| 456905 | Composite SAP note about SAPSetup as of Release 6.20 |