IF you notice any change in performance, it will be very little. It is important to note when disk performance impacts over all computer performance - and that is really only during disk reads. And for most users, that is only a small part of their computing tasks. Your boot times will be noticeable, but once your computer is fully booted, drive access is typically minimal. Load times of major applications will be noticeable, but again, once loaded, drive access is typically minimal.
The slowest SSD will run circles around the fastest hard drives so you will definitely see performance gains with a SSD - but again, this really depends on how you use your computer. If primarily for Office type tasks, reading emails, surfing the Internet, updating Facebook, once the computer is booted, the drive steps pretty much out of the way.
Did this computer used to perform fine and no longer does? If so, you might clean out the clutter with CCleaner or Disk Cleanup. Making sure you don't have too many programs starting with Windows can free up resources and improve performance too. And making sure you have lots of free disk space for Windows to operate in makes a big difference. If you disabled disk defragging, defrag after cleaning out the clutter.
And of course, make sure your system is free of malware and fully updated.
