What's eating up my PC's memory?

I have a Lenovo and recently I'm getting a message "You're computer is low on memory" even when I have only two-three tabs of google chrome open, a document or two, and notes. I have four gigs RAM. Usually restarting my laptop would fix it but now even when I start it, I get low memory. With nothing open. How can I fix this?

Added (1). When I get low memory, the programs actually crash-especially Google chrome so it isn't a false notification. Also task manager shows 95-100% memory usage.

Take a look down by your clock. See all those icons? They're using memory.
press WinLogo key + R
type "msconfig" in dialog box, without the quotes
Place a dot in Selective Startup…
Startup tab
Uncheck everything that is NOT essential.
OK out of all windows,
Then Restart computer
Pic below is of my msconfigWhats eating up my PC s memory