Saw this on a GitHub post, not sure if it's gonna help or not but it might, solved a similar issue. But before you attempt to use it, have you tried running Electrum as an administrator?
If it doesn't work...
download and install python 2.7;
download and install PyQt4;
download and unpack electrum python sources Electrum-2.5.1.zip from official download page;
run client from it's directory with "python electrum" command (make sure that python executable directory is in your PATH variable);