Invalid Window Handle

Ok mate now what did you find in that C: partition? and one more thing you can do to see how much disk space is being used is to - Start > Computer > right click that C: drive > click Properties and you should get a window come up like in my pic.
Now I am going off line in a minute as I worked last night and today has been hectic and I have to get some shuteye but am back on tomorrow. See the pic for the desktop icons you really don't need as some are duplicated on the taskbar.
Optimize Windows 7 < see point 21

Ok mate just very slowly follow this Disk - Clean and Clean All with Diskpart Command it isn't as hard as it looks you need a machine that you can hook the drive up to to run the clean all and there USB to drive adaptors to do that - the drive to be cleaned showing up a an external and given a number in DISKPART. see pic of the adaptor there are many variations but they are not expensive. It themachine you sue is a desktop then you can just hook the drive in using a spare SATA socket.

Am alternative is wipe with this Best Free Partition Manager for Windows | MiniTool Partition Free just run it and pick the drive and right click it and choose wipe - it will fill the drive with zeros.

Now funny you say that but I had a similar issue on a fix the other day with MSE so before you do anything else run these if I have not asked before
SUPERAntiSpyware | Remove Malware | Remove Spyware - AntiMalware, AntiSpyware, AntiAdware!
Malwarebytes | Malwarebytes Anti-Malware Premium
AdwCleaner Download
ADW download from bleeping computer delete any rubbish found with the malware scans

Well RR mate you can stop those addon things you usually have to untick and you just need to install this
https://unchecky.com/

Yep well there is more if you want to get the best out of your 7 machines this is my bible
Optimize Windows 7 - that is if you don't mind losing a bit of the bling like transparency - you don't have to but I don't find it absolutely necessary.


A couple of things I run all the time now on all my machines are these if you want to stay clear of the 10 stuff

the batch file for disable the upgrade from this one Upgrade to Windows 10 Update - Enable or Disable in Windows 7 or 8.1 - Windows 10 Forums

and this to keep it clear Ultimate Outsider - Software Downloads I run this one just about everyday once set up all you need to clear stuff is use the button in my pic but only download the GWX CP software

To be extra careful I set updates to what is in my pic in fact I downlaod very few updates now unless it is a fresh install and then I make a special effort to Hide KB3035533 - the 10 upgrade one.