Never defrag a SSD. No manufacture of any SSD recommend drfraging them.
I use the Intel Tool Box for my SSD. I would think every brand of SSD's have something along the same line as Intel.
You could also run this to check Windows y System Files. SFC /SCANNOW Command - System File Checker
Many times if will fix problems with Windows Explorer.
Many 3rd party anti virus don't play well with Windows 7 and cause all kinds of problems. That is why I use MSE and MAM Pro. They all play well together.
Programs I recommend I use unless otherwise stated.