Run sqldeveloper.exe (from the new place if you moved the folder out from oracle folders) as administrator and enter the jdk path that comes with your oracle installation: e.g. C:\Program Files\Oracle\11g\product\11.1.0\client_1\jdk\bin
Run sqldeveloper.exe (from the new place if you moved the folder out from oracle folders) as administrator and enter the jdk path that comes with your oracle installation: e.g. C:\Program Files\Oracle\11g\product\11.1.0\client_1\jdk\bin