Using MyDSL Extensions on HDD installs
From DSL Wiki
As noted on the MyDSL Repository extensions are not made for use with DSL installed on the hard drive. Nevertheless, many extensions do work. This page is devoted to information about using extensions for hard disk drive installs.
How the extension works depends foremost on its type. There are 4 types of extensions: tar.gz, dsl, uci and unc (see also). You'll be able to see the type with the file ending. (Note though that in the MyDSL extension tool, the file ending tar.gz is hidden.)
Tar.gz extensions should work well on hard disk installs. These extensions install themselves once on the hard drive and should work thereafter.
DSL extensions should work well on hard disk installs. These extensions install themselves once on the hard drive and should work thereafter.
UCI extensions should work, but they will need to be loaded each time. The first time you download the extension it will be saved in /tmp. In the future, click the load local button in the MyDSL extension tool. This will allow you to reinstall the extension without having to redownload it.
UNC extensions will not work on hard drive installs. Sorry :(