== CLEAN HARD UPGRADE ON WINDOWS ==
General Hard upgrade instructions are documented in [http://www.postgis.org/documentation/manual-svn/postgis_installation.html#hard_upgrade PostGIS Hard Upgrade]

You need to do a hard upgrade if you are using a pre-alpha release of a major release such as the case with PostGIS 2.0
or you are upgrading from one major version to another e.g 0.*, 1.* --> 2.*

* If you don't have perl on your windows box, download [http://www.activestate.com/activeperl/downloads ActivePerl] and install.  You can use the 64-bit or 32-bit version even if you are using 32-bit PostgreSQL. [http://www.activestate.com/activeperl/downloads].
When prompted to do so, choose to add Perl to your environment path and map to .pl scripts.

Note that ActivePerl also has packages for MacOS, Linux, but is generally not necessary for those platforms since they come prepackaged with perl.

* Create an upgrade.bat file with contents something like this:
{{{
set PGPORT=5433
set PGHOST=localhost
set PGUSER=postgres
set PGPASSWORD=yourpasswordhere
set THEDB=dnddts20
set PGINSTALL=C:\Program Files (x86)\PostgreSQL\9.1
REM note the below example is if you are on 32-bit windows choose which install path makes most sense
REM set PGINSTALL=C:\Program Files\PostgreSQL\9.1\
set PGADMIN=%PGINSTALL%\pgAdmin III
set PGBIN=%PGINSTALL%\bin\
set PGLIB=%PGINSTALL%\lib\
set POSTGISVER=2.0
set PATH=%PATH%;"%PGINSTALL%\bin\"
perl utils/postgis_restore.pl "dnddts_daily.backup" | psql %THEDB% 2> errors.txt
pause
}}}

* Right mouse click on the .bat file (you may have to choose -- Run as Administrator)