Account on my server keeps on locking out

[MilesAway]

There are 3 users who are on different location and facing a problem with account lock out. I have to them manually unlock their account every morning. I a not able to find out whey this is happening. After every 30 minutes the account is locked. I had checked all the settings which looks perfect in their place. But somehow it does not work well in Domain Controller. Can anyone tell which settings are responsible for this kind of issue.

[Kenyon]

Go and first check in local machines. Verify the user rights there and check back. You have to find out whether user account services in that are working or not. It can happen that due to failure in service this kind of problem appear. You can verify that associated services on the same must be configured automatic. There can be problem with permission also.

[Stel]

Just check one thing. Are users trying to use the account different machine. The user have map a drive on one system and then using a separate machine later on for accessible the files which is causing the problem. The map drive here fails to connect that result in account lock.