When you factory reset an OEM computer, you get all of the bloatware the vendor preinstalls and just using Add/Remove programs to get rid of what you don't want, will leave residue in the registry.
One way to remove that is with a registry cleaner, but they can be indiscriminate and hose your system and are best left alone.
The next best thing is to use a 3rd party uninstaller.
Here are a couple of articles where you can read about them -
http://dottech.org/100309/windows-best-free-clean-uninstaller-program-review/http://listoffreeware.com/list-of-best-free-uninstaller-software/The free version of Revo only picks up on 32 bit programs and not 64 bit programs so you would need to use the free trial of the Pro version for any 64 bit programs you want to uninstall - or buy it.
I use IOBit Uninstaller which does for both and prefer it to Revo because of its simpler use and find it particularly useful in uninstalling the McAfee which came preinstalled on both my Toshiba laptops.
If you do decide to install IOBit then look out for a small checked box to the right of the pre-checked EULA box.
It could be for either of any other IOBit's products, so uncheck it before clicking on Install/Next.
One program you can use to sort out the chaff and vet your Startup menu is DeCrapifier although I've never used it, as I know which programs I want rid of.
http://www.pcdecrapifier.com/ - it may also be worth running StartUpLite again as preinstalled programs can also be inserted into the Startup menu of which some, DeCrapifier may not pick up on..
CCleaner is mentioned in one of those articles and is a handy tool for clearing the temp Internet cache which when built up can have an adverse effect on the performance by slowing its operation down.
This is how to use it
https://www.piriform.com/docs/ccleaner/using-ccleaner and some tips on using it
http://www.howtogeek.com/113382/how-to-use-ccleaner-like-a-pro-9-tips-tricks/One other place to check for a build up of files is the temp folder - one machine I cleaned out had over 3GB of files in there which was slowing the computer to a crawl.
You can view this by going Start - type %temp% and press enter.
If that is highly populated then click on Organize - Select all - Organize - Delete - confirm.
There should only be a Debug file remaining so check the box then click on Skip.
If there are any large files remaining, repeat the procedure and accept the UAC if you are presented with one.
Going back to your backing up the registry - I don't know how Shane's WR program backup and restore does it but when you back up the full registry, you can't use that to restore as you cannot restore files that are in use.
Perhaps Shane can explain how WR accomplishes that.
You can however, back up and restore individual registry folders by clicking on their name - File - Export - give them a name where they will be saved as a .reg file and to restore them - File - Import - browse to the saved location - click on it then on Open where it will be reinstated.