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Currently there are two reported working methods for installing Windows XP Professional on to an SDHC card for use on the EeePC. Method 1 as discussed by CorvetteZ0606 on the EeeUser Forums. Method 2 as discussed by DonkeyBeliever makes use of nLite for the bootable CD Creation and Acronis True Image Home v11 for the clone of the XP Install. Also there is a simplification of both methods, so you don't have to bother about changing the driver-files of XP before installation using the freeware xp3eSD.