Can you please give more details about what device and when the message comes up?
Have you looked in the device manual and followed its instructions;
if this is a dedicated ereader about installing ADE (digital editions), authorizing the computer and authorizing the deivce?
When I sign it ...it comes back and says device not authorized. I know my ID and password are correct caused I have used them on here.
It is an android tablet. Adroid version 4.0.3 Model number MID9740?
This is only happening when I am trying to get my books I downloaded in the aldiko app.
Maybe the Aldiko app itself has different authorization from some other app on the tablet.
Various people have complained about issues authjoizing Aldiko properly.
Try the Bluefire app and see if it goes any better; three seem to be fewer issues with that.
Can I still get my books that are downloaded?
As long as the app is authorized with the same Adobe ID that was in use by whatever device/app was cative when the book was first accessed,
you can install multiple ereader apps and read books on any/all of them.
If you can't get Aldiko to authorize properly you may be stuck for reading the books on it.
The important thing is not to create two different Adobe IDs,
with some apps/devices and some books books under one ID and other books under the other ID.
Quite a few Adobe DRM apps (including ADE on PC/Mac) have problems with passwords that include characters other than non-accented letters and numerals.
If you have such a stronger password, log into the Adobe website using it, and change it to a weaker one (isn't Adobe security wonderful?)