On 02/12/2010 14:55, sajiimec wrote:

> Due to any failure of Delphi 7 , I reinstalled Delphi 7 and
> unconsiuously also installed Interbase. After that All my aplication
> mention above failed to be run with error message "unavailable database".

Remove all occurence of GDS32.DLL from your system and then open a
terminal session, change to Firebird's installation \bin dir and launch
the next two commands:

instclient -f i g
instclient i f

then try to reconnect.
Try testing localhost:C:\path\db.fdb TCP connection first, then local
(direct) connection (ie C:\path\db.fdb without localhost: part) through
isql tio check firebird is on and working.

Ciao.
Mimmo.