Really depends on the version of Oracle. I've seen some older versions tied to IE 6, hence requiring XP or some form of virtualization or emulation of IE 6. Newer versions shouldn't have a problem though.
My Computer
OS
Windows 7 Ultimate x64 SP1
CPU
Intel Core i3 530 2.93 Ghz Clarkdale
Motherboard
ASRock P55 PRO/USB3 LGA 1156
Memory
4 GB OCZ DDR3 1600 (PC12800) Low Voltage Desktop Memory
Graphics Card(s)
Nvidia GeForce GTX 550 Ti with 1 GB of RAM
Sound Card
Realtek HD ALC892
Monitor(s) Displays
20'' eMachines E202HDbmd Glare Panel Widescreen
Screen Resolution
1600 x 900
Hard Drives
Western Digital 1 TB Caviar Black Edition (7200 RPM) SATA
Hitachi Deskstar 500 GB (7200 RPM) SATA
Samsung SpinPoint 400 GB (7200 RPM) SATA
PSU
Rosewill Xtreme Series RX750-D-B ATX12V v2.2 & EPS12V (750W)