Error when installing RMySQL on Windows 7 - rmysql

Question

I have followed the instructions on this website for installing RMySQL on my 64 bit Windows 7 machine: http://www.ahschulz.de/2013/07/23/installing-rmysql-under-windows/
However I get the following error message: Any ideas? I have searched for some time for an answer with no luck - I wonder if the problem is the lack of a file called x86_64-w64-mingw32-gcc but I cannot figure out where this should come from or be stored.
install.packages("RMySQL", type = "source")
Installing package(s) into ‘C:/Users/lokell/Documents/R/win-library/2.14’
(as ‘lib’ is unspecified)
Warning: dependency ‘DBI’ is not available
trying URL 'http://cran.ma.imperial.ac.uk/src/contrib/RMySQL_0.10.2.tar.gz'
Content type 'application/x-gzip' length 52150 bytes (50 Kb)
opened URL
downloaded 50 Kb
* installing *source* package 'RMySQL' ...
** package 'RMySQL' successfully unpacked and MD5 sums checked
** libs
rm -f RMySQL-init.o connection.o db-apply.o driver.o exception.o fields.o result.o utils.o
"C:/PROGRA~1/R/R-214~1.1/bin/x64/Rscript.exe" "../tools/winlibs.R"
x86_64-w64-mingw32-gcc -I"C:/PROGRA~1/R/R-214~1.1/include" -I../windows/libmariadbclient-2.1.0/include -I"d:/RCompile/CRANpkg/extralibs64/local/include" -O2 -Wall -std=gnu99 -mtune=core2 -c RMySQL-init.c -o RMySQL-init.o
x86_64-w64-mingw32-gcc: not found
make: *** [RMySQL-init.o] Error 127
ERROR: compilation failed for package 'RMySQL'
* removing 'C:/Users/lokell/Documents/R/win-library/2.14/RMySQL'
The downloaded packages are in
‘C:\Users\lokell\AppData\Local\Temp\RtmpkPZRnB\downloaded_packages’
Warning messages:
1: running command 'C:/PROGRA~1/R/R-214~1.1/bin/x64/R CMD INSTALL -l "C:/Users/lokell/Documents/R/win-library/2.14" C:\Users\lokell\AppData\Local\Temp\RtmpkPZRnB/downloaded_packages/RMySQL_0.10.2.tar.gz' had status 1
2: In install.packages("RMySQL", type = "source") :
installation of package ‘RMySQL’ had non-zero exit status