Exhibit 31.1

 CERTIFICATION

I, Subramanian Sundaresh, certify that:

1. I have reviewed this Annual Report on Form 10-K of Adaptec, Inc.;
2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to statea material fact necessary to make the statements made, in light of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;
3. Based on my knowledge, the financial statements, and other financial information included in this report,fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, theperiods presented in this report;
4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosurecontrols and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financialreporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:
a) designed such disclosure controls and procedures, or caused such disclosure controls and procedures to bedesigned under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, ismade known to us by others within those entities, particularly during the period in which this report is being prepared;
b) designed such internal control over financial reporting, or caused such internal control over financial reportingto be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and thepreparation of financial statements for external purposes in accordance with generally accepted accounting principles;
c) evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this reportour conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this reportbased on such evaluation; and
d) disclosed in this report any change in the registrant's internal control over financial reporting that occurredduring the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materiallyaffected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and
5.  The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internalcontrol over financial reporting, to the registrant's auditors and the audit committee of registrant's board of directors (or personsperforming the equivalent function):
a) all significant deficiencies and material weaknesses in the design or operation of internal control overfinancial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and reportfinancial information; and
b) any fraud, whether or not material, that involves management or other employees who have a significant rolein the registrant's internal control over financial reporting.
Date:  June 6, 2007
By: /s/ SUBRAMANIAN SUNDARESH