Removing shortcut keys

[Guest]

I , somehow, have reassigned the right hand keyboard Shift key so it no longer
provides shift function but acts like a Cntrl key, it seems. Left side Shift key operates normally., How do I redefine the Right hand key? Thanks much

 

[Guest]

Further, I have discovered that the Right shift key is defined as a small box image??
How do I redefine? Thanks