Some older versions of the PC25 & PC35 headsets have some compatability problems with the Vista operating system from Microsoft and some INTEL based IMAC's

You will find below an executable firmware updater that will allow you, to update your headset.

Please follow the instructions on the screen carefully before completing the update.

License Agreement for Sennheiser Communications A/S software 
 
By installing this software program (the Software), which is licensed to you by Sennheiser Communications A/S (SeCom), you agree to the following terms and conditions (the Agreement). If you do not agree with such terms and conditions do not install the software.
 
This Agreement is a legal agreement between you or the organisation you represent and Sennheiser Communications A/S regarding the Software accompanying this Agreement.
 
All title and copyrights in and to the Software (including but not limited to any images, photographs, animations, videos, audio, music and text incorporated into the Software) are owned by SeCom or its suppliers. The Software is protected by copyright laws and international treaties.
 
DISCLAIMER OF WARRANTIES:
you agree that SeComm has made no express warranties to you regarding the software and that the software is being provided to you "as is" without warranty of any kind. SeComms disclaims all warranties with regard to the software, express or implied, including, without limitation, any implied warranties of fitness for a particular purpose, merchantability, merchantable quality, or noninfringement of third-party rights. Some states or jurisdictions do not allow the exclusion of implied warranties, so the above limitations may not apply to you.
 
LIMIT OF LIABILITY:
In no event will Secomm be liable to you for any loss of use, interruption of business, or any direct, indirect, special, incidental, or consequential damages of any kind (including but not limited to lost profits, damages to hardware and other software program) regardless of the form of action whether in contract, tort (including negligence), strict product liability or otherwise, even if SeComms has been advised of the possibility of such damages. Some states or jurisdictions do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you.
 
This Agreement shall be interpreted and governed by the substantive laws of Denmark without regard to its choice of law principles.
 
Any dispute arising out of or in connection with this Agreement shall be decided by the Maritime and Commercial Court in Copenhagen, Denmark; provided that SeCom shall also be entitled to bring an action in any court having jurisdiction over you in any case involving violation or infringement of its rights in the Software, or other intellectual property rights.