ThinkPad E420 AMD switchable graphics Windows 10

[kfzhu1229]

I am trying to save a ThinkPad E420 that the owner deemed it as junk and old and wanted to throw it away. So as usual I upgraded the poor 2GB of RAM to 8GB and then added an SSD on that thing.
However the hurtle comes when I try to put Windows 10 on it... Mine is the version that comes with AMD switchable graphics (Radeon HD 6630M) with the built in Intel HD 3000 graphics, and I am having a royal pain trying to get that to work in Windows 10.
With the drivers microsoft automatically downloaded from Windows update, it would work when it installs it but then when I reboot it goes to a blank screen and I thought it's frozen there. Apparently it is not, but it takes over a minute sitting there on a blank screen every time the laptop starts up before responding again and it gets very annoying and eliminates any speed benefits of the SSD.
I updated the BIOS to the latest version from 2013 (and also learnt the hard way you should NEVER flash the BIOS in Windows 10 because I got a bluescreen right when the software starts flashing! Fortunately it's also right before it erases anything so I didn't end up with a bricked machine! ), but it didn't help.
I tried the Windows 7 and 8 drivers provided by Lenovo, neither worked at all.
I tried to use a slightly newer driver by Sony, but can't extract them without a Sony Vaio laptop and I anticipate those to not work either.
I don't exactly need the discrete graphics to work, but at least I want the laptop to take a reasonable amount of time to start up so the owner would actually like using the laptop.
Tried disabling the switchable graphics and use integrated only, the laptop would boot up just fine decently fast, but even though the Intel HD graphics driver is properly installed, the laptop acts like as if it is not, and it is laggy and goes up to XGA only.
I know for these things, the Intel HD graphics must be using the modded drivers by AMD to work, but even with that it is still no good.
I searched online and people all just mention about the potential methods to work around to get the switchable graphics to work, but none have this annoying issue where the driver takes a long time to load.
How should I get around the latter? Any input would be appreciated.
Alternatively I guess one possibility is to trade the motherboard with its heatsink to a E420 motherboard without the Radeon graphics that's a pain in the butt to work with in Windows 10.
I am getting very frustrated and disappointed with this support, when something like a ThinkPad T/R60 has better graphics driver support in Windows 10

[kfzhu1229]

Actually I did end up figuring the solution for this, thought I should share this solution to this forum so that whomever end up with also a E420 or E520 or any model with the first gen AMD Switchable graphics with Intel HD 3000 (Radeon HD 6630M + Intel HD 3000).
The documentation for this problem is surprisingly scarce. A few forums mention this issue but they lead to nowhere.
I ended up finding two solutions around the slow driver loading problem:
1. use the 9.1.0.0 drivers from Microsoft Update catalog: https://www.catalog.update.microsoft.co ... 0098267d63
http://download.windowsupdate.com/c/msd ... fbcbf9.cab
2. Leshcat drivers - modified drivers that also fixes the switchable graphics problem and I was able to get Furmark running on discrete graphics with the latest release here: https://sourceforge.net/projects/leshcatlabs/

In either case, if you encounter the problem of device cannot start, disable both in device manager, do NOT restart, then first enable the Intel HD 3000 graphics, then enable the Radeon HD 6630M graphics, and then even if you restart it's going to work perfectly fine. In fact, this is what stopped me from using these drivers in the beginning until I figured this out.
Tested all this under Windows 10 x64, no idea if it works with x86 (not like you should because a maximum of 4GB of RAM is a huge bottleneck for the potential for a E420 anyway)

Also, do NOT let Windows update update either one of these drivers! It can break the discrete graphics functionality in case of the Leshcat drivers (HD 3000 drivers MUST be modified either by Leshcat or AMD for the switchable graphics to work!!), and flat out stop working in the case of the old drivers! If it updated your drivers, quickly update the drivers again to revert back to how it was!

On a side note, I notice the E420 has a really dumbed down version of the power beeps that you'd typically find on ThinkPads before the xx30 generation. Hibernate/sleep/resume and AC connect/disconnect all sound like the same single beep sound you get on a T3x/4x/6x ThinkPad when you press the power button to turn off the laptop in non-ACPI environment. No idea why Lenovo would use something like this to save costs or something

Now finally this E420 can find its way back to the owner without the owner wanting to throw it out, now fully cleaned inside out and with the 500G HDD replaced with a 500G WD Blue SSD and the sad 2GB of RAM to 8GB, for exactly C$100 total.