vmetnev wrote:I previously had installations of mssql
Are you sure, "mssql" (instead of MySQL)??
vmetnev wrote:Is it possible to connect previously installed mysql and FileZilla to newly installed XAMPP?
Xampp is no software, it is only a name for a distribution of a couple of software products. If you already have an MySQL(?) Installation running, you simply may use this installation instead of that, which comes with Xampp. There is no action required.
Same for filezilla.