Rename the DxfToolStd_???.ex1 file to DxfToolStd_???.exe then run
it to install the DXFTool Standard Edition.  The ??? can be either
V12, X3, X4 or X5.

The documentation is in a PDF file.

DXFTool For CorelDRAW Standard Edition.pdf

Windows Vista:

CorelDRAW V12 is not supported on Windows Vista.

CorelDRAW X3, X4 and X5 are supported on Windows Vista
but be sure to have all the service packs installed.

Due to some installation constraints you must disable
the UAC (User Access Control) before installing the
DXFTool Standard Edition.  on Windows Vista.  The
licensing system will NOT work correctly if you do
not disable the UAC.

The following article shows an easy way to do this.

http://www.howtogeek.com/howto/windows-vista/disable-user-account-control-uac-the-easy-way-on-windows-vista/

Windows 7:

CorelDRAW X3, X4 and X5 work on my Windows 7 test computer
but I don't think X3 will be supported by Corel.  X4 and X5
will be supported by Corel.  I was unable to install SP1 for
X3 on Windows 7, but SP2 for X3 installed without any issues.
Caveat Emptor.

Due to some installation constraints you must disable
the UAC (User Access Control) before installing the
DXFTool Standard Edition on Windows 7.  The licensing
system will NOT work correctly if you do not disable
the UAC.