Summary of significant accounting policies (Tables)

3 Months Ended

Jan. 31, 2012

Accrued product warranty and deferred warranty revenue activity is as follows:



	Three Months Ended January 31,
	2012			2011
(in millions)
Balance, at beginning of period	$	598		$	506
Costs accrued and revenues deferred	111			81
Adjustments to pre-existing warranties^(A)	123			9
Payments and revenues recognized	(106		)	(90		)
Balance, at end of period	726			506
Less: Current portion	324			250
Noncurrent accrued product warranty and deferred warranty revenue	$	402		$	256

_______________

(A)

Adjustments to pre-existing warranties reflect changes in our estimate of warranty costs for products sold in prior periods. Such adjustments typically occur when claims experience deviates from historic and expected trends. Our warranty liability is generally affected by component failure rates, repair costs, and the timing of failures. Future events and circumstances related to these factors could materially change our estimates and require adjustments to our liability. In addition, new product launches require a greater use of judgment in developing estimates until historical experience becomes available. In the first quarter of 2012, we recorded adjustments for changes in estimates of $123 million, or $1.76 per diluted share. Net of tax, the adjustments for changes in estimates amounted to $81 million, or $1.16 per diluted share.