PRINT THIS IF USEFUL FOR REFERENCE:
The original W8 speed may simply be what it performs at, especially if a slower CPU like many of the AMD, or Intel Celeron processors.
W10 should be almost identical to W8 though.
This sounds like:
a) missing driver, or
b) failing main drive (HDD/SSD), or
c) data corruption
Things you can try:
1) confirm GPU is supported (for AMD I think only HD5000M and later has support for W10)
2) don't install drivers if uncertain they are supported.
3) add the Intel software too to scan for drivers:
https://downloadcenter.intel.com/
other:
4) Buy an SSD, then install W10 to it directly (don't clone).
a) backup important data, passwords etc to a USB drive (can buy a USB adapter to copy back later, but some stuff may need to be copied with Windows running)
b) write down program names to reinstall later for easy reference
c) buy an SSD such as the Samsung 850 256GB (see pcpartpicker)
- many laptops use 7mm height
- test if possible in another PC, or via a USB adapter->
https://www.amazon.com/SANOXY-inch-Drive-Adapter-Cable/dp/B003Z2NIH2
recommended:
https://pcpartpicker.com/product/3kL7YJ/samsung-internal-hard-drive-mz75e250bam
lower budget solution:
https://pcpartpicker.com/product/gf98TW/a-data-internal-hard-drive-asp550ss3240gmc
I use the BlacX dock for $30 which supports 2.5" and 3.5" HDD and SSD drives. It's quite handy as you can swap drives (unmount and shutdown though). The USB3 version may have problems.
https://www.amazon.com/Thermaltake-Sata-HDD-Docking-Station/dp/B0012Z3MKW/ref=sr_1_5?s=pc&ie=UTF8&qid=1467108413&sr=1-5&keywords=blacx
$20 right now and should work about the same as BlacX:
https://www.amazon.com/Cable-Matters-Drive-Docking-Station/dp/B0099TX7O4/ref=sr_1_8?s=pc&ie=UTF8&qid=1467108413&sr=1-8&keywords=blacx
For non-Prime you need $50 or more for shipping so this plus an SSD might make sense. One I linked, or Kingston V300 for $65 so it's about $100USD+ roughly to upgrade if you get both items.
5) Install the SSD
6) boot to the W10 media (link to create at end of post)
7) do NOT enter a key when prompted (MS will assign one as it can detect you had W10 installed before)
8) finish MS updates
9) setup wi-fi password
10) install anti-virus
11) test for performance
12) make a BACKUP IMAGE to a USB drive if possible (Windows backup or similar)
13) open Device Manager (right-click Start) to see if anything missing
If any issues now, then ask again online. Windows 10 should install most drivers. The only issues I've had are:
a) older AMD drivers not supported
b) multi-GPU setups not supported (need switching software like NVidia Optimus to switch between Intel and NVidia GPU, and W10 may not auto download the proper software for that)
c) Card reader (though earlier OS drivers have worked in everything I tried. That includes a Vista driver working for W10 with an 8-year-old laptop)
Summary:
Hope that helps.
If you have issues still, or don't think an SSD would help then try to be as SPECIFIC as possible about the performance issue.
To me, it sounds a lot like a failing hard drive.