I’m using TeamCity Version 4.5.3 (build 9035) and today I really couldn’t remember my password. After searching for a while and trying various solutions, I have found this one working perfectly.
Open a command prompt and go to <installation folder>\webapps\ROOT\WEB-INF\lib folder. Now type the following :
..\..\..\..\jre\bin\java.exe -cp server.jar; common-api.jar;commons-codec-1.3.jar;util.jar;hsqldb.jar ChangePassword username newpassword
Notes : Change your Java.exe path accordingly. In this case I use the one located in the TeamCity folder.