Windows 7, disconnects from the database with the following error: "ORA-03113". This error is also replicated when tested in sqlplus and the Oracle client Enterprise Manager.
If the same ORA-03113 is happening in SQLPlus and Oracle client Enterprise Manager, then it is likely not be a Toad issue.
However the following steps below can be applied to help resolve the issue
We do support Windows 7 including 64bit.