This is a small problem that occurs only on one of three Windows 7 computers I have, but it's driving me nuts. I cannot get to the bottom of it. Any help would be most welcome. I'm running Windows 7 Home Premium on a Dell XPS 210 (computername: Dee-PC) on my home network. The print service changes my default printer setting at seemingly random times. Under Control Panel/Printers and Faxes, I have six printers configured, four of which are located on other networked PCs. The other two (#s 1 and 3) are virtual devices: 1. Fax 2. HP Officejet 4300 Series on Mel-Aspire-1810 3. Microsoft XPS Document Writer 4. Canon MP-830 Fax on Mel-PC 5. Canon MP-830 Series Printer on Mel-PC 6. Epson PictureMate Deluxe on Mel-PC I manually set #5 as the default printer through the Control Panel, and a few days later I find that it has been set to #4. This has happened many times over the past few months, ever since I first installed Windows 7 (a clean install of the retail version). Looking into the Applications and Services Logs in Computer Management, I find many instances of Event 823 in the PrintService/Admin log: Changing the Default Printer. On almost all of these instances under the event details, I find the item DefaultPrinterSelectedBySpooler under User Data set to 1. The only time this item is different is for the event corresponding to my manual selection of the #5 printer as the default, several days earlier. For that one event, the value is 0. When I manually re-set the printer to #5 again, it generates this same event, with the DefaultPrinterSelectedBySpooler set to 0. Close examination of this log shows my manual selection of #5, then no activity for several days, then suddenly the print service begins repeatedly setting the default printer, flailing between #2 (this host is a laptop not on the network for the last couple of weeks), and #4 over several minutes, eventually settling on #4. Looking at the system and application logs, I see no other event correlated to this, although the system log shows that my PC does repeatedly go to sleep and then wake up again moments later, whenever no one is using it. I don't know why this happens, but it seems to occur pretty constantly when no one is working at it, and it doesn't seem to trigger a default printer reset, at least 999 times out of 1,000.