You have an audit trail.  Go to Reports > Company > Audit Trail.  This is why you should not share passwords and everyone should have their own sign in name.   

Note on Sage 50 passwords:

No one needs to know your password, not even a manager.  They have their own password and don't need yours.  If you feel your password has been compromised, change it next time you sign in.   

Also, the IT department can be an Admin of one of the Sample companies to make modifications to Sage 50.  They don't need the Admin password of your active company.