Hey all,

I have a dual boot Ubuntu 10.10 and WinXP SP 3 on my Dell Vostro 1510 laptop. Whenever I switch OSs, the clock gets reset to, as far as I can tell, GMT-1, even though I have my timezone set on both to GMT-5.

I am sure this problem has been seen before, so can someone point me in the right direction?

A potential solution is listed here: http://serverfault.com/questions/161...-windows-clock

but I am rather new at this, so I would like confirmation that that is worth trying before I start messing around in /etc.

On a recent Ubuntu you should be able to cchange the clock from the GUI - just look for a tick-box for UTC. Other than that the linked post is pretty right.

Windows wants the time in your local timezone, while Linux defaults to Universal Time Code (you just see your local time in linux because it gets calculated using timezone information). When Windows shuts down, it saves the local time in your BIOS memory. When Linux starts, it interprets this value as Universal Time - which is wrong. When Linux shuts down, it saves Universal Time to BIOS, which is then interpreted wrong by Windows.

You have to consider both systems to use UTC, or both to use Local time: The option mentioned by syg00 in Ubuntu's control center should do.

Or make Windows use UTC: Start registry editor, Navigate to

and edit (or create) a DWORD value:
with value 1.

I use the latter method, however from time to time something mysteriously makes windows interpret the time as local again (without changing the registry key or writing the wrong time to BIOS on shutdown). I have configured NTP time updates in Windows' Control Center to counter this.