Us Patent Nos 4603 Driver For Win7 23l
in case of a regression, you can theoretically revert, but that requires separating the print server from its delivery service. windows server 2003 sp1 (and earlier) and windows 7, including r2 (and earlier) have rather basic isolation in case of regression. that means that a job can still receive its print data, but the print server won't open the spooler.
Us Patent Nos 4603 Driver For Win7 23l
as long as a not-present printer driver doesn't load, no driver bugs can make their way into the print server. this is important because there is a class of driver bugs known to cause a major operation that can take a spool queue down for hours if not longer. such an operation requires unloading and reloading the spooler service and all of the driver stacks.
the drawback is that vista and earlier do not have that mechanism. a classic example is the print drivers that windows xp did not ship with . these drivers each include a module (activeprint.dll) to send status and printer properties to spoolsv.exe.
should very old drivers fail to load, windows 7 and server 2008 r2 have a bit of a panic. the print server will drop spooler service and all printer drivers and, as the documentation advises, you'll end up with a bunch of seriously corrupted data in your network print queues.
since one cannot predict what else people will put on drivers, it is important to place the printisolationhost.exe in system32 rather than the usual system folder. it is also critical that the process be started each time the computer boots, for as long as the spooling services are to remain available.