<PAGE>

                                                                    Exhibit 31.2

                            CERTIFICATION PURSUANT TO
                  SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Brian Fontana, certify that:

1.    I have reviewed this annual report on Form 10-K/A (Amendment No. 1) of
      I-Sector Corporation.

2.    Based on my knowledge, this annual report does not contain any untrue
      statement of a material fact or omit to state a material fact necessary in
      order 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;

3.    Based on my knowledge, the financial statements, and other financial
      information included in this annual report, fairly present in all material
      respects the financial condition, results of operations and cash flows of
      the registrant as of, and for, the periods presented in this report;

4.    The registrant's other certifying officers and I are responsible for
      establishing and maintaining disclosure controls and procedures (as
      defined in Exchange Act Rules 13a-15 (e) and 15d-15(e)) for the registrant
      and have:

      a.    designed such disclosure controls and procedures, or caused such
            disclosure controls and procedures to be designed under our
            supervision, to ensure that material information relating to the
            registrant, including its consolidated subsidiaries, is made known
            to us by others within those entities, particularly during the
            period in which this report is being prepared.

      b.    evaluated the effectiveness of the registrant's disclosure controls
            and procedures and presented in this report our conclusions about
            the effectiveness of the disclosure controls and procedures, as of
            the end of the period covered by this report based on such
            evaluation; and

      c.    disclosed in this report any change in the registrant's internal
            control over financial reporting that occurred during the
            registrant's most recent fiscal quarter (the registrant's most
            recent quarter (the registrant's fourth quarter in the case of an
            annual report) that has materially affected, 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
      my most recent evaluation, to the registrant's auditors and the audit
      committee of registrant's board of directors (or persons performing the
      equivalent function):

      a.    all significant deficiencies and material weaknesses in the design
            or operation of internal controls over financial reporting which are
            reasonably likely to adversely affect the registrant's ability to
            record, process, summarize and report financial information; and

      b.    any fraud, whether or not material, that involves management or
            other employees who have a significant role in the registrant's
            internal control over financial reporting.

Dated:  April 11, 2005

/s/ Brian Fontana
---------------------------
Brian Fontana

Chief Financial Officer