Exhibit 99.1

Company contacts:
Bob Blair
Investor Relations
949.672.7834
robert.blair@wdc.com

Steve Shattuck
Public Relations
949.672.7817
steve.shattuck@wdc.com

FOR IMMEDIATE RELEASE:

WD^® ANNOUNCES Q1 REVENUE OF $2.7 BILLION AND
NET INCOME OF $239 MILLION, OR $1.01 PER SHARE

Company to Update Impact of Thailand Floods in Today’s Conference Call

IRVINE, Calif.—Oct. 19, 2011—Western Digital Corp. (NYSE: WDC) today reported revenue of $2.7 billion, hard-drive unit shipments of 58 million and net income of $239 million, or $1.01 per share, for its first fiscal quarter ended Sept. 30, 2011. The company’s results include expenses of $21 million associated with the planned acquisition of Hitachi Global Storage Technologies (Hitachi GST) announced Mar. 7, 2011 and unrelated litigation accruals. Excluding these expenses, non-GAAP net income was $260 million or $1.10 per share.¹

In the year-ago quarter, the company reported revenue of $2.4 billion, net income of $197 million, or $0.84 per share, and shipped 51 million hard drives.

The company generated $352 million in cash from operations during the September quarter, ending with total cash and cash equivalents of $3.7 billion.

¹ Non-GAAP net income for the first quarter of fiscal 2012 consists of GAAP net income of $239 million plus $21 million of acquisition-related expenses and unrelated litigation accruals. Non-GAAP earnings per share of $1.10 for the first quarter is calculated by using the same 237 million diluted shares as is used for GAAP earnings per share. The tax effect of the acquisition-related expenses and unrelated litigation accruals was not material.

WD Announces Q1 Revenue of $2.7 Billion and
Net Income of $239 Million, or $1.01 Per Share
Page 2

Conference Call

The investment community conference call to discuss these results will be broadcast live over the Internet today at 2 p.m. Pacific/5 p.m. Eastern. As previously reported, the company will also provide an update on the impact of the recent severe flooding in Thailand on its operations in the Bangkok region, along with its outlook for the December quarter. The live and archived conference call webcast can be accessed online at www.westerndigital.com/investor, click on “Conference Calls.” The telephone replay number is 800-568-4850 in the U.S. or +1-203-369-3813 for international callers.

About WD

WD, one of the storage industry’s pioneers and long-time leaders, provides products and services for people and organizations that collect, manage and use digital information. The company designs and produces reliable, high-performance hard drives and solid state drives that keep users’ data accessible and secure from loss. Its advanced technologies are configured into applications for client and enterprise computing, embedded systems and consumer electronics, as well as its own consumer storage and home entertainment products.

WD was founded in 1970. The company’s storage products are marketed to leading OEMs, systems manufacturers, selected resellers and retailers under the Western Digital^® and WD^® brand names. Visit the Investor section of the company’s website (www.westerndigital.com) to access a variety of financial and investor information.

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Western Digital, WD, and the WD logo are registered trademarks of Western Digital Technologies, Inc. All other trademarks mentioned herein belong to their respective owners.

WESTERN DIGITAL CORPORATION

CONDENSED CONSOLIDATED BALANCE SHEETS

(in millions; unaudited)

	Sept. 30,		Jul. 1,
	2011		2011
ASSETS
Current assets:
Cash and cash equivalents	$	3,675	$	3,490
Accounts receivable, net		1,356		1,206
Inventories		645		577
Other		250		214
Total current assets		5,926		5,487
Property, plant and equipment, net		2,209		2,224
Goodwill		151		151
Other intangible assets, net		67		71
Other assets		114		185
Total assets	$	8,467	$	8,118
LIABILITIES AND SHAREHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	1,708	$	1,545
Accrued expenses		348		349
Accrued warranty		135		132
Current portion of long-term debt		163		144
Total current liabilities		2,354		2,170
Long-term debt		100		150
Other liabilities		290		310
Total liabilities		2,744		2,630
Total shareholders’ equity		5,723		5,488
Total liabilities and shareholders’ equity	$	8,467	$	8,118

WESTERN DIGITAL CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF INCOME

(in millions, except per share amounts)
(unaudited)

	Three Months Ended
	Sept. 30,			Oct. 1,
	2011			2010
Revenue, net	$	2,694		$	2,396
Cost of revenue		2,153			1,959
Gross margin		541			437
Operating expenses:
Research and development		193			167
Selling, general and administrative		89			59
Total operating expenses		282			226
Operating income		259			211
Net interest and other		(1	)		—
Income before income taxes		258			211
Income tax provision		19			14
Net income	$	239		$	197
Income per common share:
Basic	$	1.03		$	0.86
Diluted	$	1.01		$	0.84
Weighted average shares outstanding:
Basic		233			230
Diluted		237			234

WESTERN DIGITAL CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(in millions; unaudited)

	Three Months Ended
	Sept. 30,			Oct. 1
	2011			2010
Cash flows from operating activities
Net income	$	239		$	197
Adjustments to reconcile net income to net cash provided by operations:
Depreciation and amortization		158			150
Stock-based compensation		17			19
Deferred income taxes		9			—
Changes in operating assets and liabilities		(71	)		24
Net cash provided by operating activities		352			390
Cash flows from investing activities
Purchases of property, plant and equipment		(134	)		(200	)
Cash used in investing activities		(134	)		(200	)
Cash flows from financing activities
Employee stock plans, net		(2	)		9
Repurchases of common stock		—			(50	)
Repayment of long-term debt		(31	)		(25	)
Net cash used in financing activities		(33	)		(66	)
Net increase in cash and cash equivalents		185			124
Cash and cash equivalents, beginning of period		3,490			2,734
Cash and cash equivalents, end of period	$	3,675		$	2,858