Another train of thought:
1 - how much CPU/RAM does the system have?
2 - when did the slowdown first become noticable?  Has it always been slow or is it...

A nice easy QOTD... but one of those things that is good to know in case you are trying to do math on real numbers and get an answer that...

What does your cbs.log file look like?  That should better point to what the error condition is.

what is the contents of your cbs.log file (C:/Windows/logs/cbs/cbs.log)?

That should also indicate why it failed to install.
Also, have you installed KB3005628?  That was a patch so you...

I agree with everyone here.  You will want to set a max for the memory.  We had ours set to what we thought was good, then got some big SSIS...

Another thing to check is your error log.  That should indicate why .NET didn't install.  
Which version of windows are you installing this on?

Another thought - what is your max memory for your SQL instance set to?
SSIS operates on different memory than the SQL Instance as would the web instance.  You leave...

2 thoughts - is the data encrypted?  If so, did you bring across the decryption keys when you restored the database?
and does the account on the local copy have...

If you have the ISO already downloaded, you can grab any zip extraction tool (winrar, winzip, 7zip, etc) and use that to extract the files to a folder and install...