I found this happen @ Mathematica 10 pre test version and formal English version.
Copy a file from windows, then paste into FrontEnd cell, you'll get a path, such like
"C:\\Users\\Hyper\\Documents\\b"
This is Ok.
However, in the Chinese character case
"C:\\Users\\Hyper\\Documents\\新建文件夹"
This is bad. [It's fine before version 10.0]
choose a file then Shift+Right-Mouse-Click, and
Copy as path, then paste into FrontEnd cell, you'll get a path, such likefile1="C:\Users\Hyper\Documents\b"file2="C:\Users\Hyper\Documents\新建文件夹"file3="C:\Users\Hyper\Documents\b\新建文件夹"
So, two methods to get path from windows system both work badly, ie
FileExistsQ[file1]==>False
FileExistsQ[file2]==>True
FileExistsQ[file3]==>False
I have many old files in Chinese path, they cannot be dealt conveniently by Mathematica 10.0@Windows now.
I should manually delete a backslash in the path string, and if I use another method to get file path, \b, \hello these names are annoying.

Is this a simple bug? Why not just keep it the same as that in Version 9?
\b,\hellothese names are annoying. – HyperGroups Aug 11 '14 at 10:11