Arduino Uno - Problems with software in Windows 7 PRO

[system]

Although properly installed Arduino (1.0.5) software does not work on Windows 7 Pro x64, but it works in Windows XP Service Pack 3.

The Arduino UNO hardware is properly recognized by the system (COM) on both Windows XP and Windows 7 (usually COM5). Where did I go wrong? My PC is a DELL Inspiron 15 with Intel Core2 Duo E6400, 4GB RAM.

Thanks for help.

[JimboZA]

My setup is very similar, works fine. See attached....