Hello..
    I seem to have lost my minimize track arrows which sit just left of the VU meters in track view. 2 little gray arrows that point up or down..can anyones help me this? All help is much appreciated..
 
Thanks

this is also referred to as the expand/collapse button..

If you have Auto Track Zoom enabled in Track View menu, they will disappear. The focused track will expand to whatever height you set, and all others will be minimized. Shift+Z to toggle it on and off.

That was it and thanks so much!! I have another question when I auto zoom a track and the others minimize..when I undo auto zoom they are still minimized..how do I get back to orig settings? also the same thing with fit to track (typing f) how do I get back to orig settings? Thanks again and I need to learn these shortcuts..

It's not possible to recover all the individual track heights from before ATZ was enabled or Fit was executed. You'll either need re-Fit with an appropriate window size or maybe minimize them all and zoom the vertical track view.
 
You might find it useful to use Auto Track Zoom and/or Fit in another Screenset so it doesn't mess up the one with customized track heights.

Thank you so much again! my last question..the other day I stumbled upon a way to change a track's height to the whole screen..(instead of increasing the zoom) I was thinking I clicked on the track name and while holding a key down? the track name with the wav files..
 

I think I found it...just hold down the Z key while dragging through a track..again thanks so much for your help
 

Double-clicking a track header will maximize it, and double-clicking it again will restore it to its previous height. I use this a lot.