Any help would be appreciated...

So a few months back i bought Icewind Dale Enhanced Edition on steam, Since then i've had to play it in windowed mode to prevent the most of the lag. but playing it in windowed is really annoying. ive already set all the graphics settings down but it still lags alot. and ive tried updating my drivers but it wont let me. So can anyone tell how to fix this? here are my system specs
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https://forums.geforce.com/default/topic/528502/nvdia-geforce-6150se-nforce-430/
'Program Options', 'Disable Cosmetic Attacks', '0',
'Program Options', '3D Acceleration', '1',
'Program Options', 'Maximum Frame Rate', '30',
'Program Options', 'Translucent Shadows', '1',
'Game Options', 'Environmental Audio', '1',
'Game Options', 'Tiles Precache Percent', '100',
Kotor 1 and 2, both run very well
Undertale, Perfectly
Crawl, again perfectly