I got some mails in which I was asked to describe the solution to the “liblto_plugin-0.dll not found” problem a bit more detailed. So let us assume that you installed (or plan to do that) all versions of gcc previously obtained from equation.com as subdirectories of the folder “X:\myCompilers” (myCompilers might be a path name!). Let us further assume, for example, that you decided to call these subdirectories “gcc461” and “gcc470” according to the version numbers of the gcc suites during the installations. At least, this convention will turn out to be a smart idea. After having firstly saved the environment variables to disk and secondly having erased all references to gcc from them, you might then want to create a DOS batch file called “go_gcc.bat”, for example, in the root directory of drive “X:”. Two lines of this batch file then set two environment variables to the values required by a specific gcc version obtained from equation.com:

set PATH=X:\myCompilers\gcc%1%2%3\bin;E:\Projekte\COMPILER\gcc%1%2%3\libexec\gcc\i686-pc-mingw32\%1.%2.%3;%PATH%
set EQ_LIBRARY_PATH=X:\myCompilers\gcc%1%2%3\i686-pc-mingw32\lib

Of course, you have to use the saved information about the path names on your PC in order to correctly substitute all the symbolic paths names used in this post. Finally, if you want to use gcc and thus start cmd, you only need to enter “X:\go_gcc 4 6 3” in order to enable version 4.6.3 of the gcc suite, for example. If you plan to install multiple versions of gcc, it is even smarter to use “gcc_x.y.z” as folder names, as you then only need to use a single batch variable that holds the value of “x.y.z”:

set PATH=X:\myCompilers\gcc_%1\bin;E:\Projekte\COMPILER\gcc_%1\libexec\gcc\i686-pc-mingw32\%1;%PATH%
set EQ_LIBRARY_PATH=X:\myCompilers\gcc_%1\i686-pc-mingw32\lib

You would want to start this batch file typing in “X:\go_gcc 4.6.3”.

I hope things are obvious now.