Downgrade or download previous version of DS?

Hi

I love to use DS since 3yrs.

I just download and installed v4.0. It seems to not good for my PC that looked very buggy (graphic issues) and I cannot utilize it at all. Could someone help download previous ver 3.2 or downgrade v4.0 to v3.2? This is serious problem with me ...

 

I checked a blog and that author said "DSv4.0 doesnt work well with Win8" 

 

I understood Dassault System wouldn't allowed old ver DS but old version was much reliable and more solid...  

 

Regards,

Jake 

Win8 32bit, JP OS, Lenovo x230i,