Goodwill and Purchased Intangible Assets (Details 2) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Apr. 30, 2013	Oct. 31, 2012
Purchased intangible assets
Amortizable purchased intangible assets, accumulated amortization	$ (5,835)	$ (5,281)
Finite-lived Intangible Assets, Accumulated Impairment Losses	(4,330)	(4,330)
Amortizable purchased intangible assets, net	3,866
Purchased intangible assets, gross	14,034	14,126
Purchased intangible assets, net	3,869	4,515
Amount of fully amortized intangible assets	118
"Compaq" trade name
Purchased intangible assets
Amortizable purchased intangible assets, gross	1,422	1,422
Amortizable purchased intangible assets, accumulated amortization	(37)	(18)
Indefinite-lived Intangible Assets, Accumulated Impairment Losses	(1,227)	(1,227)
Amortizable purchased intangible assets, net	158	177
In-process research and development ("IPR&D")
Purchased intangible assets
Indefinite-lived purchased intangible assets	3	7
Customer contracts, customer lists and distribution agreements
Purchased intangible assets
Amortizable purchased intangible assets, gross	5,800	5,807
Amortizable purchased intangible assets, accumulated amortization	(2,859)	(2,625)
Finite-lived Intangible Assets, Accumulated Impairment Losses	(856)	(856)
Amortizable purchased intangible assets, net	2,085	2,326
Developed and core technology and patents
Purchased intangible assets
Amortizable purchased intangible assets, gross	6,497	6,580
Amortizable purchased intangible assets, accumulated amortization	(2,795)	(2,501)
Finite-lived Intangible Assets, Accumulated Impairment Losses	(2,138)	(2,138)
Amortizable purchased intangible assets, net	1,564	1,941
Other product trademarks
Purchased intangible assets
Amortizable purchased intangible assets, gross	312	310
Amortizable purchased intangible assets, accumulated amortization	(144)	(137)
Finite-lived Intangible Assets, Accumulated Impairment Losses	(109)	(109)
Amortizable purchased intangible assets, net	$ 59	$ 64