Product updates can contain updates for system reliability, program compatibility, security, etc.
You can acquire product updates in two ways:
For SolidWorks 2008, by using the Installation Manager to check for, download, and install updates.
You can initiate the Installation Manager manually, or schedule it to periodically check for updates.
For older versions of SolidWorks, by downloading service packs manually from the SolidWorks support Web site.
Service packs are applied as patches to an existing software version. For example, SolidWorks 2007 SP1.0 is a service pack for SolidWorks 2007 SP0.0. You install these service packs using the SolidWorks Installation Manager that corresponds to the major version you are updating; you cannot install them using the SolidWorks 2008 Installation Manager.
For instructions on downloading and installing service packs, see the installation documentation for the SolidWorks version you are updating.
Updates
downloaded by the SolidWorks Installation Manager and service packs downloaded
from the SolidWorks Web site are different kinds of files. They should
never be downloaded to the same location.
SolidWorks Installation Manager