From the Eclipse downloads page:
Installing Eclipse in Program Files directory on Vista
By default, Microsoft Windows Vista does not allow user level accounts to write
files in the “Program Files” directory. This can prevent Eclipse from starting
when installed in the “Program Files” directory, because Eclipse stores
configuration data by default in its install directory. Either of the following
workarounds can be used to avoid this problem:Install Eclipse outside the “Program Files” directory
Instruct Eclipse to store configuration data outside the “Program Files”
directory using the -configuration command line argument. The problem will
not occur when running Eclipse as the Administrator user, but this is not
recommended because it compromises the Windows Vista security model.
(https://bugs.eclipse.org/bugs/show_bug.cgi?id=168445)
There was no such disclaimer for Linux.
During that time…