InstallShield Run As local account if not ran by admin - installshield

Question

I have a InstallShield InstallScript project that needs to be ran with administrative rights. In a nutshell from the InstallShield I need to:
Detect if the installer currently has administrative privileges.
If setup.exe is not being ran with admin rights spawn a new instance of the setup.exe using a local admin account/password then close the old (non-privledged) setup.exe.
So far I know I can do something like this to find if I have admin rights:
//---------------------------------------------------------------------------
// Run As Utilities Library
//---------------------------------------------------------------------------
// Include Ifx.h for built-in InstallScript function prototypes.
#include "Ifx.h"
//---------------------------------------------------------------------------
export prototype UserRightsCheck();
function UserRightsCheck()
begin
MessageBox(INSTALLPROPERTY_INSTALLLOCATION, INFORMATION);
if(USER_ADMINISTRATOR) then
MessageBox("hello Admin", INFORMATION); // testing only
// do nothing we are an admin
else
MessageBox("hello user", SEVERE); // testing only
RunAsAdmin();
endif;
end;
export prototype RunAsAdmin();
function RunAsAdmin()
begin
STRING username = "myUserID";
STRING password = "myPassword";
STRING filepath = INSTALLPROPERTY_INSTALLLOCATION;
RunAsUserAccount(username,password,filepath);
end;
export prototype RunAsUserAccount();
function RunAsUserAccount()
STRING username;
STRING password;
STRING filepath;
begin
/*
Is this the best way to do this? this is the function I need help with
This seems like a hack
*/
if ( SYSINFO.WINNT.bWinXP ) then
LAAW_SHELLEXECUTEVERB = "open"; // target PC is on Windows XP
else
LAAW_SHELLEXECUTEVERB = "runas"; // Windows 7 (or Vista)
endif;
LaunchApplication(
filepath
,"" // Arguments
,"" // Directory
,SW_NORMAL // Use Window Mode
,0
,LAAW_OPTION_WAIT_INCL_CHILD | LAAW_OPTION_USE_SHELLEXECUTE
);
end;
How do I relaunch the installer though? This can be done in Wise Package Studio and many other tools but I haven't found the answer how to do it in this one yet.
I know I could probably do a runas.exe or psexec.exe but that feels like a hack and sounds like a poor practice. After about a day of reading I am still not sure how to do this though.
Could someone please point me in the right direction of the proper way to do this in InstallShield?

Answer 1

Tell the user in the MessageBox to relaunch the setup with admin rights. Explain that they can do this by right clicking the setup.exe in Explorer and then clicking "run as admin" and then OK in the UAC prompt. This is the conceptually "clean" way to do it, since you are doing nothing unexpected.
As I have already stated in the comment above, do think twice about Installscript MSI. It is extremely buggy. The better option is a Basic MSI with Installscript custom action code.
A basic MSI is a standard MSI, and the Installscript custom actions do not interfere with the setup GUI or the overall MSI operation. In Installscript MSI the whole installation sequence is Installscript controlled, and this causes serious bugs - some of which have no workarounds or fixes (even years after their discovery).

Answer 2

Perhaps this is along the lines of what you are looking for: How can I make the installer Run as admin. Also check this.
If you use an MSI instead of Installscript and use the built-in MSI concept of elevated rights, you can use MSI properties set at the command line to install anywhere with elevated rights: msiexec /i MySetup.MSI USER=OneUser /PASS=PassWord /qn. Just stating what is possible and perhaps easier.