Hello,
Sorry to hear you are having issues. Those Windowblinds you download from Wincustomize.com, you should be able to install it by double click on its ".wba" files. If its in a zip file you will need to unzipped/uncompress it first and a ".wba" files should be in it.
Let us know if you need more help.
Basj,
Stardock Community Assistant.