Login Window Not Showing Database TNS Entry

[Irfi]

I am running windows7 with oracle 11g/R2 on 64-bit environment. Just right now, I have installed the pl/sql developer utility and find that: its not showing Database TNS entry infact its showing empty. I am using this utility from last 5 yrs and its my very first experience. Any guidance/support.

Regards
Irfan Ahmad

 

[IvanZ]

PLSQLDev can only interact with 32-bit Oracle client as of now.