>> I have copied the folders back to the base dir (like C:\PostgreSQL
>> \data
>> \base\16404) if that's step one but what after that?
>
> Just start Postgres. If the data dir is ok, it should run fine.
It's unclear from your description whether the raw DB files were
moved from another installation - note that the above is only
guaranteed to work if architecture/compiler/etc. are all the same.
If the files were created by exactly the same PG instance, then you
should be okay.
- John D. Burger
MITRE