Excel Interop cannot open my file!

So a while back I made a website that uses the Excel interop (long story). Since I made it a while ago, the IIS configuration is not automated, and must be done artisanally.

Recently I have been working on moving it to a new server. I installed Excel, and the website.

Everything seemed ok until sysprep happend!

So I immediately was not pleased. First I started ripping apart everything profile related with IIS, and nothing.

Eventually I stumbled across something on stack overflow to summarize make sure C:\Windows\SysWOW64\config\systemprofile contains a folder called Desktop. If you are on 32 bit you need c:\Windows\System32\config\systemprofile to contain the Desktop folder.

Pretty much desperate, and out of options I gave it a shot. Somehow it was the fix, although it pains me to say this.