how/can you use a recorded track such as guitar or bass for more than one project?

for example i want to copy the bass from an older version of a song into the new version.

i have renamed the samples so that they are easy to find but i cannot find them in the acid project area where all the projects are saved

Hey Martin, I am trying to understand your question, when you record something into Acid, they all get saved in a specific folder which you set in Preferences. I am guessing you may not have checked it and all your recordings are going into a default folder. But still, I am not sure if I understand your question clearly. You may have to elaborate.