In computing, runas (a compound word, from “run as”) is a command in the Microsoft Windows line of operating systems that allows a user to run specific tools and programs under a different username to the one that was used to logon to a computer interactively. It is similar to the Unix commands sudo and su, but the Unix commands generally require prior configuration by the system administrator to work for a particular user and/or command. Microsoft Windows The runas command was introduced with the Windows 2000 operating system. Any application can use this API to create a process with alternate credentials, for example, Windows Explorer in Windows 7 allows an application to be started under a different account if the shift key is held while right-clicking its icon. The program has the ability to cache verified credentials so that the user only ever has to enter them once. Syntax The command-syntax is: runas [{/profile | /noprofile}] [/env] [/netonly] [/smartcard] [/showtrustlevels] [/trustlevel:<TrustLevel>] [/savecred] /user:<UserAccountName> program Parameters This section is paraphrased from the runas /? command. /noprofile: Speeds up the loading of the application by skipping the loading of the user's profile. Note that this might not speed up every application. /profile: Do not skip loading the user's profile. This is the default setting. /env: Use the actual environment, not the user's. /netonly: Specifies that the given credentials are to be used for Remote access only. /savecred: Credentials saved by the previous user. This setting is not available on Windows 7 Home or Windows 7 Starter Edition. This setting is left out from Windows XP Home Edition as well. /smartcard: Specifies that the credentials will be supplied from a smartcard. /user: Format is either USER@DOMAIN or DOMAIN\USER. /showtrustlevels: Shows help (list of usable trust level parameters) for the /trustlevel switch. /trustlevel: One of the trust levels listed by the /showtrustlevels switch. program: Command line for the executable file. See examples below. Note: Only type in the user's password, when the system asks for it. Note: The /profile switch is not compatible with the /netonly switch. Note: The /savecred and the /smartcard switches may not be used together. Examples runas /noprofile /user:machine\administrator cmd runas /profile /env /user:domain\admin "mmc %windir%\system32\dsa.msc" runas /user:user@domain.example.org "notepad C:\filename.txt" runas /user:administrator /savecred "shutdown /i" Inferno The command is also included in the Inferno operating system. Syntax runas writes the user to /dev/user and invokes cmd with the given