ruby script/plugin install not working

I have mingGW32 , and cygdrive ....

I made a git clone ..... perfect....

I intent to use git... $ ./script/plugin install git://.....
it did not work, PLUGIN NOT FOUND...

I used in the console C:\ Windows\system32\cmd.exe

C:\ path.......>.ruby script\plugin install git:// or...... http://

it works...
but

It copy only the dir carpets or foulders ....

RAILS .... /vendor/plugin/2dc_qgrid/ .....
but at the end the carpet 2dc_... is empty.....

Can you help me.... I spend much time....

the plugin is...............2dc_jqgrid.git................