I've forgotten my sa password and already disabled windows authentication mode.
How can I reset SQL Server sa password with disabled windows authentication
tnx in advance
I had the same problem. Tried googling it and all the standard solutions didn't work so I had to get creative. Essentially my problem was that the SA account was disabled, also the system was set to only allow login by windows authentication, and finally the administrator account in windows also was not a member of the sysadmin role. So all the normal suggestions kept giving me permission denied errors (because I didn't have permissions to alter what other posts were telling me I should alter).
My solution is documented below, only apply the parts you need:
Stage 1: - Get SSMS working in single user mode
Stage 2: Part 1: - Enabling SQL Server and Windows Authentication mode
Stage 2: Part 2: - Adding yourself into the sysadmin role
Stage 2: Part 3: Altering the SA Password and enabling the account
This is the process for resetting any users password (for a sysadmin). At this stage you should close SSMS.
Stage 3: Restarting SSMS in multi user mode.
Stage 4: Trying on your bigger shoes.
At this stage you should be able to enable or disable the SA account from your login and change its password, also you should be able to enable or disable the ability to login with SQL Server authentication. Test these to ensure you have necessary rights.
Notes: Some taught should go into doing this. I feel that a sysadmin account should be the first thing setup once you setup a new SQL server instance.
Some people recommend removing the SA account (Personally, I recommend just putting a really strong password on it). As long as you have an account with sysadmin this is fine but someone must have an account with sysadmin access. This account should not be named Admin or some variant thereof like God for obvious reasons. Also avoid names such as your business name and combinations of either etc.
As regards to enabling or disabling sql server authentication that's a debate I'll leave for the DB admins.
Hope you find this helpful.