geo, depends entirely on why you're upgrading:
If they're having issues with opening multiple spreadsheets simultaneously or overall sluggishness when when multiple programs are open, then checking to see if it will support 8GB of RAM would be the best upgrade.
If they're upset by how long it takes to load windows or to launch a file, then a solid state would likely be the best upgrade.
If they're running a data analytics program and it's taking forever to process, then it's time to look at a new generation of laptop for a faster processor.
Or, as many of my execs like to do, they may just want something shiny and new to make them look special in a meeting.