Tried 6.0 Beta, guess I messed up

[frybo30]

I have the Standard Version. I didn't like 6.0 Beta, so I re-
downloaded v5.2. Things don't seem right; very slow response to
every command. I did not remove 5.2 before downloading 6.0 Beta, and
I did not remove 6.0 Beta before re-downloading v5.2. Should I have?
If so, should I now remove v5.2 and start all over with the current
version, which I believe still is 5.2? If so, how do I do that and
still have the paid-for Standard version? Thank you.