read about hp's international warranty here
HP lies on it's warranty, BEWARE
from their website
Global Warranty and FAQs - HP Customer Care (United States - English)
What is not covered by HP Global Warranty
HP Global Warranty does not offer an identical warranty everywhere in the world. HP Global Warranty does not change or affect HP Service Agreements, HP Service Contracts, support services bundled with HP hardware, or HP SupportPacks.
HP will not alter form, fit or function of the product to make it operate in a country for which it was never intended to function, for legal or regulatory reasons.
i dont know about SonyVaio. will try to google. it's not pretty.
mostly i see are complaints about Sony's International warranty.