What kind of electrical shock can that be?
First you should look at your grounding electrode system.

Then you should look out for lost neutrals, which can cause voltage to rise as high as 400V on 230V-nominal legs on a 400V "wye". 

Finding none of those, you should look at the quality of the equipment - an awful lot of PC equipment is cheaply made foreign garbage with frequent failure rates, especially in the developing world. It is possible the failures have nothing to do with power quality. Going out of your way to get well-regarded power supplies can help a lot.  

Finally, look at localized surge protection at the equipment.