Have been using EMC for a year or two, but lately it has been loosing the activation code and I have to re-install it.

1

Keeps loosing activation code

2

Are you by any chance using the same activation code on another computer?

If you are, that may be the reason as a license is only valid for a single computer. If it is a Free License, you will need to register a separate one for each additional computer. If it is a Pro License, you will need to purchase an additional one for each computer.