By default, attempting to use the wrong Windows user account password five times will lock the user account for 30 minutes. It will automatically unlock once the 30 minutes expires. In addition to being a default setting on most Windows servers it is a PCI-DSS requirement (section 8.5 of the PCI Self-Assessment Questionnaire).
If you have a Domain Server: Open Administrative Tools > Active Directory Users and Computers and find the appropriate user account. Note: You can search for a user account by right-clicking on the domain name in the left pane and clicking “Find…”

Right-click the appropriate user account and click Properties.

Select the Account tab and un-check “Unlock account”. Click OK to apply the changes and exit.
If you have a workgroup server: Open Administrative Tools > Computer Management. Expand Local Users and Groups on the left pane and select the Users folder. On the right pane, right-click the appropriate user account and click Properties. From the General tab check-box “Unlock Account” and click OK to save and exit.
