Windows 8.1 Unable to Install SQL Server

I am trying to install SQL Server on a VM of Windows 8(.1). I installed it before, but then I deleted the VM and created an identical copy. Now, I can't seem to install it at all. This was all on a Windows 8.1 host, with a Windows 8 guest from my school (seems to be a Developer or preview edition). I forget my process the 1st time, but this was my process this time:

1. Install Guest Additions, then update with Windows Update, then update to Windows 8.1 from the Windows Store, then more updating from Windows Update.

2. Install Visual Studio 2013. I'm not sure if this matters, but given how incompatible MS products are with each other, I'm putting it here.

3. Attempt to install SQL Server 2012, failing every time, right at the very end.

4. Troubleshoot SQL Server installation. It gets cryptic errors, which I look up. They seem to have to do with .NET 3.5 not being installed, so I go to Programs & Features and attempt to enable .NET Framework 3.5 (includes .NET 2.0 and 3.0), the first "feature" in the list. This fails.

5. Troubleshoot enabling .NET 3.5. The error seems to be that I can't connect to the Internet, but I am connected to the Internet, and can go to several pages in Google Chrome from both guest & host. I try different networks, I try turning off Avast! (host) and Windows Firewall (guest), but still nothing, so I give up and try something else.

6. Troubleshoot enabling .NET 3.5 more. There is another method on the bottom of the MS support page, saying to enter the command DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /Source:E:\sources\sxs /LimitAccess. It installs .NET 3.5 right from the Windows 8 installation media (why this couldn't be done when installing Windows 8, I can't fathom). I try it (E: is the drive with the installation disk), but get the error:

   Error: 0x800f081f

   The source files could not be found. Use the "Source" option to specify the location of the files that are required t o restore the feature. For more information on specifying a source location, see http://go.microsoft.com/fwlink/?LinkId=243077.

   The DISM log file can be found at C:\WINDOWS\Logs\DISM\dism.log

7. Troubleshoot this new error. When I Google the error (0x800F081F), it says Windows Update is probably corrupt or something similar and to clean Windows Update by entering the commands dism /online /cleanup-image /scanhealth and dism /online /cleanup-image /restorehealth, in that order, but these 2 find nothing wrong, yet when I try the previous command, it still reports errors. Now, I finally give up and come here, to StackOverflow.

8. Troubleshoot some more with Stack answers. I try Enable-WindowsOptionalFeature -Online -FeatureName 'NetFx3' -Source 'd:\sources\sxs', suggested by @bjorn. This fails with the output:

   Enable-WindowsOptionalFeature : The source files could not be downloaded. Use the "source" option to specify the location of the files that are required to restore the feature. For more information on specifying a source location, see http://go.microsoft.com/fwlink/?LinkId=243077. At line:1 char:1

   • Enable-WindowsOptionalFeature -Online -FeatureName 'NetFx3' -Source 'e:\sources\ ...
   • ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     • CategoryInfo : NotSpecified: (:) [Enable-WindowsOptionalFeature], COMException
     • FullyQualifiedErrorId : Microsoft.Dism.Commands.EnableWindowsOptionalFeatureCommand

The cmd and PowerShell commands seem to claim that I didn't specify a source, or at least that I didn't specify a source with the correct files in it, but I used what claims to be a Windows 8 installation media, and did seem to install Windows 8, from my school. Is it possible this CD was an early version without support for the features I'm trying to obtain?

Also, the Programs and Features option claimed that I was not on the Internet, or otherwise couldn't establish a connection, but I was on the Internet and successfully visited several sites like Google. It's funny to me that the help article MS directs you to for directions to get on the Internet itself requires the Internet to view, but that's another matter. Is it possible that my VM wasn't set up properly or something to that effect?

What's happening with my SQL Server 2012? Is there some incompatibility with Visual Studio 2013? This is on a VM with virtually nothing else on it. Besides the usual settings configuration, it has maybe 3 programs, none of which should have anything to do with these MS products. Also, why was I able to install SQL Server before, on essentially the same VM, yet now I am not?