The disapearing software

Recently installed a printer, HP 842C, on my computer, Windows ME, using USB. Software holds for a few days, then an error message appears stating the printer is not connected, and a yellow question mark appears when you go to SYSYEM, DEVICE Manager, USB. HP offers no help, citing the fact that the software installed and worked. Compaq, the computer manufacturer, offers no help-they also are responsible for the Windows software, so Microsoft won’t help. Any suggestions?