Minecraft will not open when launcher says it has been multiple times.

My computer has had a lag, so when I try to go on launcher, it says it is open but I see nothing! I try to open it again and it says it is already open. This is some details.

1 I have windows 7
2 It is opening for windows 7 in properties
3 I had windows defender scan it multiple times
If any one can help plz do.