Note: RaQuest needs Enterprise Architect. You can't use RaQuest without Enterprise Architect.

• Microsoft® Windows 2000 (SP4 or later), Windows XP (SP3 or later), Windows Vista, Window 7
• Enterprise Architect 6.0 or later version
  Floating License Version requires Enterprise Architect 6.1 Build 788 or later build (version). License Manager's version must be 1.3 or later version.
• 20 MB of available hard-disk space .
• 1024x768 screen resolution preferred for showing lists and manipulate Requirement items - 800x600 useable, 640x480 not suitable.
• RaQuest can't use with Linux.

Link:
Enterprise Architect's System Requirements