have a older copy of photoshop elements 1.0 and the serial key that came with it wont work. its not a bootleg i bought the software. what do I do to get it valid?

Photoshop Elements will not install on Windows version 7 and up without a trick. See:

Photoshop Elements (PSE) knowledge base.

If you follow the instructions Elements 1 will even work on Windows 10, it seems. Although I fail to see the point, seeing that open source and free software is available which is far more up to date in terms of features.

You bought the software recently or back in 2001 when photoshop elements 1 was the current version adobe was selling?

The serial is 24 digits, no letters, just numbers staring starting with 1057.

(the X's below represent numbers)

1057-XXXX-XXXX-XXXX-XXXX-XXXX

So make sure your entering the right numbers.

You may even need to look at the serial with a magnifying glass to be sure.