As long as you have the key files for each program you are good to go. The serial numbers won't help you when trying to register.
If you don't have key files for a program you already purchased you can try the
Key Recovery webpage using your email address you originally used when purchasing. The key(s) you request will be sent to that email address.
If you don't have key files and you no longer have access to the email address you can request keys AND change your email address with Slysoft by using the
contact form.
After getting all your key files download the latest version of each program and install them. Check each program's forum for any current newer beta versions. If there are any use those instead of the release versions on the main Slysoft site.
When installed register each program using the needed key file for each program.