Exhibit 4.5

         NEITHER THIS OPTION NOR THE  SECURITIES  ISSUABLE UPON EXERCISE  HEREOF
         HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. THEY
         MAY  NOT  BE  OFFERED,   SOLD  OR  TRANSFERRED  IN  THE  ABSENCE  OF  A
         REGISTRATION,  OR THE  AVAILABILITY OF AN EXEMPTION FROM  REGISTRATION,
         UNDER SAID ACT.

                           OPTION ASSUMPTION AGREEMENT

         AGREEMENT  dated as of August 12, 1999, by and between  AMERICA ONLINE,
INC., a Delaware corporation with its principal office at 22000 AOL Way, Dulles,
Virginia  20166 (the  "Company"),  and Robert D. Lord, an  individual  currently
residing at 710 Agave Court, Sedona, Arizona 86336 (the "Holder").
         1. Existing Stock Option.  The Company hereby  acknowledges that Holder
was granted an option (the  "Option")  to acquire  300,000  shares of the common
stock of Nullsoft, Inc. ("Nullsoft"), for an aggregate exercise price of $3,000,
pursuant  to Section  1(d) of the  Employment  Agreement  dated  October 1, 1998
between  Nullsoft,  Inc. and Holder.  The Company further  acknowledges that the
consummation of the acquisition of Nullsoft by the Company  constituted the sale
or transfer of majority  ownership  of Nullsoft  and,  consequently,  the Option
automatically  vested by its terms.  The Company further  acknowledges  that the
Option has been  assumed by the Company and  converted  to an option to purchase
shares of the Company's common stock,  $.01 par value (the "Common  Stock"),  in
accordance  with the  provisions  of the  Agreement  and Plan of  Reorganization
related to the acquisition and,  following such  conversion,  that the Holder is
entitled,  subject to the terms set forth  below,  to purchase an  aggregate  of
22,272 shares of the Common Stock at an exercise  price equal to $0.14 per share
(the "Assumed Option").
         2.   Assumed Option.
                  (a) The Assumed  Option shall be  exercisable by the Holder at
any time, or from time to time, in whole or in part, upon submitting a Notice of
Exercise  signed by the Holder,  together with payment of the exercise  price to
the Company by cash, check or wire transfer.
                  (b) Any unexercised portion of the Assumed Option shall expire
at the close of business on October 1, 2008 (the "Expiration  Date"). The Holder
may  exercise the Assumed  Option by notice to the Company  signed by the Holder
and  setting  forth the number of shares of Common  Stock to which the  exercise
relates,  accompanied  by payment of the exercise price therefor plus the amount
required to be withheld by the Company in connection  with such  exercise  under
federal,  state and local tax laws.  The Company shall deliver to the Holder one
or more  certificates  registered  in the name of the  Holder  representing  the
shares of Common Stock purchased by the Holder.
                  (c) If, prior to the  Expiration  Date,  there shall occur any
stock  dividend,  stock  split,  combination  of  shares,   reclassification  or
recapitalization  with respect to the Common Stock or a consolidation  or merger
as to which the Company is not the surviving corporation, then to the extent the
Assumed  Option is  unexercised,  the  number of shares of Common  Stock and the
exercise price shall be equitably adjusted.
                  (d) The shares of Common Stock  received  upon exercise of the
Option shall not be  transferable  by the Holder except in  compliance  with the
Securities  Act of  1933,  as  amended,  and  any  applicable  state  laws.  All
certificates  for shares of Common Stock  purchased  under this  Agreement in an
unregistered  transaction  shall  bear the  following  legend  (and  such  other
restrictive legends as are required or deemed advisable under any state statute)
to reflect such restriction:

         THE SHARES  REPRESENTED BY THIS  CERTIFICATE  HAVE NOT BEEN  REGISTERED
         UNDER THE  SECURITIES  ACT OF 1933,  AS AMENDED (THE "ACT"),  HAVE BEEN
         ACQUIRED FOR INVESTMENT, AND MAY NOT BE SOLD, PLEDGED,  HYPOTHECATED OR
         OTHERWISE TRANSFERRED UNLESS A REGISTRATION  STATEMENT UNDER THE ACT IS
         IN  EFFECT  WITH  REGARD  THERETO  OR  UNLESS  AN  EXEMPTION  FROM SUCH
         REGISTRATION IS AVAILABLE.

         3.  Nonassignability.   No  right  or  benefit  under  this  Agreement,
including  the Assumed  Option,  shall be  assigned,  transferred,  pledged,  or
encumbered by the Holder.
         4.  Notices.   Any  notice,   request,  or  other  communication  given
hereunder,  other than a notice of exercise of the Assumed  Option,  shall be in
writing and if given by the Holder to the  Company,  shall be sent by  certified
registered  mail,  postage  prepaid,  addressed to the Company at 22000 AOL Way,
Dulles, VA 20166,  Attn: Vice President of Human Resources,  and if given by the
Company to the Holder  shall be  delivered  personally  or sent by  certified or
registered  mail,  postage  prepaid,  addressed to the Holder at his address set
forth above.  Notices,  requests and other  communications shall be deemed to be
given when received,  which,  in the case of notice given by mail,  shall be the
time indicated on the receipt therefor.
         5. Notice of Exercise of Assumed  Option.  The Holder  shall submit the
Notice of Exercise of the Assumed Option to the Manager,  Stock Group, AOL Human
Resources Department,  in accordance with the procedures established and then in
place for the  exercise  of  options by  employees  or former  employees  of the
Company,  as  applicable.  The  Holder  may  address  questions  related to such
procedure to "Stock Help" at (703) 265-2516.
         6. Entire Agreement. This Agreement contains the entire agreement among
the parties  hereto with respect to the  assumption  and terms of stock  options
issued  by  Nullsoft  to  Holder  and   supersedes   all  prior   agreements  or
understandings,  written or oral,  among the parties with respect  thereto.  The
parties hereto  acknowledge  that this Agreement does not modify or supersede in
any respect the Agreement and Plan of Reorganization  related to the acquisition
of Nullsoft by the Company. The parties further agree that any agreement between
the  parties  with  respect to the  issuance of options in  substitution  of the
Option,  including the Option  Agreement  (the "First Option  Agreement") by and
between the  Company  and  Holder,  dated as of May 28, 1999 which may have been
mistakenly entered into and which mistakenly provided for the issuance to Holder
of an option to purchase  22,286 shares of the Common Stock,  is now deemed null
and void. This provision is not intended to and does not supersede or modify the
terms of any  agreement  between the parties  entered  into in  connection  with
options  granted by the Company to the Holder under the Company's 1992 Employee,
Director  and  Consultant  Stock  Option  Plan  on or  after  the  date  of this
Agreement.
         7. Applicable Law. This Agreement shall be governed by and construed in
accordance with the laws of the State of Delaware,  without giving effect to the
conflict of law principles thereof.

         IN WITNESS WHEREOF, this Agreement has been duly executed by the Holder
and on behalf of the Company by its duly authorized  officer,  all as of the day
and year first above written.

                                      AMERICA ONLINE, INC.


                                      By:________________________


                                      HOLDER:


                                      /s/ ROBERT D. LORD
                                      Robert D. Lord