My laptop has Win7 64 Bit and I haven't had any issues installing a UI, and getting it to appear ingame correctly.
So, here's a question:
Where are you attempting to put the UI folder?
With a 'normal' launchpad install of the game, the path should look similar to this:
C:\Program Files (x86)\Sony Online Entertainment\Installed Games\Vanguard
(I don't install via the launchpad, so it might be slightly different for you.)
For a 'Steam' install of the game, the path IS this:
C:\Program Files (x86)\Steam\steamapps\common\vanguard saga of heroes\
If neither of these are your install path, locate the folder Vanguard is installed to. If it installed to something like:
"C:\ProgramData\" with no space in the address, you're going to need to tell Station Launcher to move your install somewhere. When I first installed on my laptop using the launcher, thats where it put the game, and you are most likely not going to be able to use a UI mod. I wasn't able to.
If this is the case for you, don't worry, it won't attempt to reinstall the game completely. The launcher will move the whole folder to the new install directory.
Inside of the install directory is another folder called "VGUIAssets". Located inside of this folder, is yet another folder called "Shells".
Your UI mod should be inside of its own folder inside of the "Shells" folder.
Pretending you're attempting to install DroxUI - since you really haven't given us ANY information aside from your OS - your folder structure should be like so:
Nested inside of the droxui should be something along the lines of:
If, for example, your structure looks like:
Then you have unzipped the mod incorrectly. Fix the nesting issue by moving all of the contents of the second droxui folder to the first one. If not, ignore this step.
The next step is to go to this folder:
In this folder, locate a file called "VGClient.ini".
If you cannot see file extentions, change the folders view to "Details", and sort by type. It will show as VGClient, with "Configuration settings" shown in the 'Type' column.
Open this file in NotePad, and hit Ctrl F. Type in "[UI]" without the quotes.
There should be a line that starts with "ShellName=". If it is not already changed to reflect whatever UI mod you are using, change where it says "ShellName=Default" to the folder name of your UI - in my example, it would be "ShellName=droxui". Save.
If you can't save, copy the VGClient file to your desktop, edit it again there, then copy it back, letting it Move and Replace in the dialog menu.
Load the game, and see if the mod loads now.
If not, reply again and tell us what mod you are using, and where Vanguard is installed to.
Either way, hope this helps
Not much of a poster - more of a lurker - but thought I would try and help.