There are risks in running XP connected to the internet. Please see the following page for what you can do to make the machine (a little) more secure if you can’t update to later Windows:
https://forum.audacityteam.org/t/important-information-for-windows-xp-users/37650/1
You cannot use Audacity with no disk space. Do you mean you had disk space but the malware was misrepresenting the free disk space?
If you did have sufficient disk space, Audacity should not be freezing that often. Do you do anything in particular that makes the freeze happen?
If the same projects or recovered projects were always freezing, the best approach is to export all projects as separate WAV files, then restart Audacity. Import the first WAV, save as a new project. File > Close, import the next WAV, save as a new project, and so on.
If any AUTOSAVE files are empty then the only chance is to force quit Audacity in Task Manager and use the “1.2 Recovery Utility” to piece together the temporary data for each project. This only works if these are unedited recordings, otherwise the timestamps of the files no longer match their position on the Timeline. The Instructions are at http://manual.audacityteam.org/man/recovering_crashes_manually.html.
Note that because you are not using the current 2.1.2 version of Audacity, your default Audacity temporary folder will not be as stated on that page but at C:\Documents and Settings<your user name>\Local Settings\Temp\audacity-temp.
Gale