Exhibit 31.2
CERTIFICATION
I, Clay C. Williams, certify that:
| (1) | I have reviewed this annual report on Form 10-K/A of National Oilwell Varco, Inc. for the fiscal year ended December 31, 2007; and |
| (2) | Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report. |
Date: March 13, 2008
| By: | /s/ Clay C. Williams | |||||
| Clay C. Williams | ||||||
| Senior Vice President and Chief Financial Officer | ||||||