A fresh install is usually a good thing every 2-3 years, it does improve things no end.
However, it might be worth a quick clean and tidy just to see if that improves it.
Quick couple of things - how much memory (RAM) has the netbook got? You should really have as much as you can cram in, I have a Toshiba one and upgrading it from 1GB to 2 made a real difference.
Try disabling Windows updates, W7 update has issues that can use up all the CPU making the PC virtually stop.
Try Ccleaner from Piriform.com, and run the clean part and the registry cleaner.
Is there at least 20-25% free on the hard drive?
A lot of laptops and netbooks have the Windows install on a hidden partition, a magic f key on boot forces a re-install, no media needed. Most netbooks have no DVD drive so may be worth downloading a W7 ISO to a USB stick.
If sticking with W7 would get either Never10 or GWX control panel to stop W10 installing. A program like Belarc Advisor can retrieve the W7 license key but bear in mind OEM ones can refuse to re-activate.
Most importantly, back anything you want to keep and/or important up to external media. Make a list of any programs you want as they will need installing again.
Also consider if you really need it to be Windows at all - I changed mine to Linux Mint over a year ago and have no regrets. If you use it purely for the Internet and Office docs it works better than Windows imo. You may need to get used to Firefox as a browser and Libre Office, but it doesn't take long.