Unless these are programs download and run directly from the internet, it is rare (very rare) for them to use other than the TEMP directories shown by a command line listing of your path:
Start, Run, cmd
set
Even in this instance you can control it by setting the Environmental settings for TEMP and TMP under System Properties, Advanced, Environmental Variables in the "top" box away from the user profile and to a non-conflicting folder you create with similar TEMP variables in the "bottom" box. I hope that makes sense, but you usually have at least 3 and often more temporary storage location environomental variables, and you want to leave the defaults alone in the "bottom" box.
Having said all that, now you want to write a .bat or .cmd file to delete the files in each directory you have identified in the "top" box. You want to use the XP scheduler to do this at Startup, rather than at Logon. Use the standard DOS syntax for the DEL /q command with full pathing.
Now having said all of that, here is a terrific freeware tool to use instead of sageset as a directable solution for any Folder you point it to:
Read the FAQ, it is perfectly batchable.
Let me end with a note: other than an instance of a download of an installation file that you specify to "Open" or "Run" rather than as a pure download, you should be perfectly safe scheduling the cleanup you have planned. One reason is that the Run key used by InstallShield and MSI installations has precedence over your batch file in the run order of things on your system.
Best wishes,
Bill Castner