hwclock --hctosys will do it - run a batch file?
Or have ntpdate run automatically as the system boots?
If you mean that Debian shows a different time to Windows consistently - check that one OS isn't resetting the other's clock. You can persuade Windows _not_ to reset the clock on daylight saving time changes, for example - or you can make sure that they both run in the same timezone and change at the same time.The Debian-specific command:
ntpdate-debian
will run to the ntp pool set by Debian so that you don't have to specify an NTP server