Unity freezes whenever I Build App

• Whenever I build my game it freezes at "Building Additional Assets"

and then I either have to

• Restart my computer

• Close Unity through Task Manager

I have been searching the internet for HOURS!!!! and I can't seem to find the problem!!

Thanks in advance

Edit: I waited about 1 hour and while it was building it just stopped and gave me 2 errorsFirst

First: UnauthorizedAccessException: Access to the path "Temp\StagingArea\NetworkTest_Data\Managed\Mono.Security.dll" or "C:\Users\Alex B\Desktop\Graphics\Random FPS\Random\NetworkTest_Data\Managed\Mono.Security.dll" is denied. System.IO.File.Copy (System.String sourceFileName, System.String destFileName, Boolean overwrite) (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/mcs/class/corlib/System.IO/File.cs:124) UnityEditor.FileUtil.UnityFileCopy (System.String from, System.String to, Boolean overwrite) (at C:/buildslave/unity/build/Editor/Mono/FileUtil.cs:207) UnityEditor.FileUtil.CopyDirectoryFiltered (System.String source, System.String target, Boolean overwrite, System.Func`2 includeCallback, Boolean recursive) (at C:/buildslave/unity/build/Editor/Mono/FileUtil.cs:142) UnityEditor.FileUtil.CopyDirectoryFiltered (System.String source, System.String target, Boolean overwrite, System.Func`2 includeCallback, Boolean recursive) (at C:/buildslave/unity/build/Editor/Mono/FileUtil.cs:156) UnityEditor.FileUtil.CopyDirectoryFiltered (System.String source, System.String target, Boolean overwrite, System.Func`2 includeCallback, Boolean recursive) (at C:/buildslave/unity/build/Editor/Mono/FileUtil.cs:156) DesktopStandalonePostProcessor.CopyStagingAreaIntoDestination () (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/DesktopStandalonePostProcessor.cs:193) DesktopStandalonePostProcessor.PostProcess () (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/DesktopStandalonePostProcessor.cs:25) UnityEditor.WindowsStandalone.WindowsDesktopStandalonePostProcessor.PostProcess (BuildPostProcessArgs args) UnityEditor.PostprocessBuildPlayer.Postprocess (BuildTarget target, System.String installPath, System.String companyName, System.String productName, Int32 width, Int32 height, System.String downloadWebplayerUrl, System.String manualDownloadWebplayerUrl, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:316) UnityEditor.HostView:OnGUI()

Second: Error building Player: UnauthorizedAccessException: Access to the path "Temp\StagingArea\NetworkTest_Data\Managed\Mono.Security.dll" or "C:\Users\Alex B\Desktop\Graphics\Random FPS\Random\NetworkTest_Data\Managed\Mono.Security.dll" is denied.

Second Edit: I completely uninstalled Unity and still gave me errors I have no idea WTF is going on but this is annoying the f*ck out of me!!!!!!!!!!!