We have been using Dell computers for several years now, back to GX1xx series.  Just recently, we've started having time and date problems.  The PC's affected are varied.  I have some 745, 760, 620, 150, all Optiplex PC's.  A lot of forums are pointing to CMOS batteries, but some of these computers are brand new.   BIOS varies from 2005 to 2007 to 2001(gx150).  No viruses found, no malware found, no odd software found.  We can't find a common point between the machines with the issue. 

In order to fix it, you have to fix it at the BIOS level becuase the system won't let you log in.  We have a dual directory environment with Microsoft AD and Novell eDir.

Could I have this many random bad batteries?  Is there a brand/series of batteries that Dell purchase that are failing?

Thanks.