You cannot do anything. You MUST run the installer as an administrator.
As for the application, you will also need to run it as an administrator with elevated privileges, but there are options for it to automatically request elevation through the application manifest. You can do a search on stackoverflow.com because there are more posts related to this problem.
, .
UAC:
UAC.
#, VB.net - .
Windows. , . SYSTEM, .net vb6.