Restart with the Shift key held down and remove the file from the Extensions folder, then restart. See Figure 1.
Figure 1: Desktop Printer Extension file.
If you have experienced other issues since installing Mac OS 8.5 please read the About Mac OS 8.5 Read Me and Installing Mac OS 8.5 Read Me that come with Mac OS 8.5.
This information is from article 58129: "
Mac OS 8.5: About Mac 0S 8.5 Read Me".
Note: Desktop printing still works under Mac OS 8.5; just the Desktop Printing Extension is incompatible.