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Ragnarok Online System Requirements

OS Windows 98se/me/2000/XP
CPU Pentium - 500 or equivalent
(Athlon CPU, Celeron)
RAM 128 MB or higher
VGA Video Card DirectX compatible video card with 8MB video memory, DirectX 8.0 or higher.
SOUND Sound Card DirectX compatible sound card
Other Other 2.2GB or higher Hard Drive space.

Probably, yes. XP is needed to have 3D. Install the GA in safe mode, else 3D won't work (is in the manual).