I've pretty much just moved to Windows 10 and I've installed Fallout 2. I tried it not long ago in the same computer with Windows 7 and I had no problem at all then. Now it doesn't matter how many or little (or zero) community patches, mods, etc. that come recommended in the Fallout 2 mods thread I install, the problem persists. I've also tried the solution that I saw being proposed somewhere in these forums of either renaming ddraw.dll or removing it from the installation folder, but that didn't solve it for me.

The slowdowns problem tends to start either from the character creation screen or from the loading screen and persists during the whole game. The mouse cursor also feels very jittery and slow when in any of these screens, not in the very main menu.

Since it seems we don't have a support page for Fallout games anymore in GOG since all the Bethesda pulling the games off of GOG thing, I turn to you guys. Any suggestions?

Thanks in advance.

How about checking INI files if DX9 mode was enabled?

ddraw.ini

[Graphics]
;Set to 0 for 8 bit fullscreen
;Set to 4 for dx9 fullscreen
;Set to 5 for dx9 windowed
;A dx9 mode is required for any graphics related script extender functions to work (i.e. fullscreen shaders)
;Modes 1, 2 and 3 are no longer supported
Mode=4

...and...

[Misc]
;Set a number of milliseconds to idle each input loop
;Set to -1 to disable
;Set to 0 to idle only if other processes are waiting for processor time
;Set to 1 (or some higher number if needed) to prevent 100% cpu use
ProcessorIdle=-1


f2_res.ini

[MAIN]

; Affects Windows Vista/7/8 and above. Allows hi-res patch settings to be changed without admin privileges
; if installed in the "Program Files" directory.
; When UAC_AWARE=0 the hi-res patches settings will be stored in the game folder as usual.
; When UAC_AWARE=1 the hi-res patches settings will be stored in the users roaming app data folder.
; For Vista this is usually "C:\Documents and Settings\'your user name'\Application Data\Fallout2".
; For Windows 7/8 this is usually "C:\Users\'your user name'\AppData\Roaming\Fallout2".
UAC_AWARE=0

; Set GRAPHICS_MODE=0 to enable Basic mode which supports resolution change only(required for sfalls Graphic modes).
; Set GRAPHICS_MODE=1 to enable Direct Draw 7 mode.
; Set GRAPHICS_MODE=2 to enable DirectX9 mode.
GRAPHICS_MODE=2

I don't have Win10 (and it looks like I'll never switch to this f*kin OS joke).

I got it working using Mash's high resolution patch. Extract to your game folder, set your native resolution in the config (and enable the patch). Use DX9 mode, 2X scaling, refresh rate 0, then go to manually edit the config and set windowed_fullscreen to 1.

I'd highly recommend starting with Killaps unofficial patch
http://www.nma-fallout.com/showthread.php?178620-Unofficial-Fo2-patch-thread-problems-reports-suggestions

It's almost completely just bugfixes.

I wouldn't recommend starting with restored content mod, but that's because I'm bit of a puritan.