Codec issues

Hello   I recently downloaded a licenced copy of Premier Elements 10 to a new computer running Windows 10. I also transferred some existing videos I previously created in this same Elements 10 on a computer running Vista.

When I try to open them I get a message stating there is a codec error.

I am not all that computer savvy and Adobe themselves told me the only place for help was the forum.

Some searching seems to suggest this happens a fair bit.

Any advice would be welcome, Thanks in advance.