I would use the repositories but in 8.04 Adobe isn't there.

Thanks for correcting me on removing a .deb - makes sense when one
thinks about it. But still got the same problem. After removal if one
does a google on .pdf - one gets a screen window

"Could not launch Adobe Reader 8.1.3. Please make sure it exists in
PATH variable in the environment. If the problem persists, please
reinstall the application."

Before pdf were just downloaded and then read with Evince. So a config
file is left somewhere i imagine.