The other day I decided to try installing Qt 4.6.0 from the SDK binary download. I already had an existing install of MinGW, located in C:\MinGW, so I chose not to install the bundled copy of MinGW. Other than that, I chose the default configuration for the rest of the Qt 4.6 installation, and it completed without any problems. I then updated my Qt-related path variables, which previously pointed to my existing Qt 4.5.0 installation directory in C:\Qt\2009.01, to point to the new Qt 4.6.0 installation in C:\Qt\2009.05. I did not change my MinGW environment variable, which remains set to C:\MinGW\bin.

The problem is that when I now try to use the make command in any context, I get an error saying that it can't be found. If I revert my Qt environment variables to point back to the 4.5 installation in C:\Qt\2009.01, make works again. What is the problem here?

Thanks.