I started this thread last year - so would like to update it. Thank you to those that helped.
It seems that somehow tax files folder became hidden due to some inadvertent name change. Since I didn't have a memory of the folder name, I had no idea where to look for a year later. I don't know what caused that folder name change as PC is a shared between multiple users. But, I did manage to get old tax files back after spending a lot of time searching for them one folder at a time with some file explorer tools. That was a big relief.
However, the lesson learnt is that one should always print your taxes. I now keep a printed copy too. Secondly, I also started backing up my tax files and a pdf version to online cloud drive (Google/Microsoft).
