sorry for the late reply, I have been very busy in college with new projects. Also thanks for responding.
That's interesting I have not heard of SAI, is it free? I will definately have an experiment when I get round to it. I am sure there are many ways of using paintbrushes in photoshop and general repetition being such a versatile tool but any image editor will be just as good.
Possible Solutions - broken laptop
Also about your laptop, sorry to hear that. Same thing happened to my friends laptop since it is so old now (and mine :/), it is like 10 years old.
Maybe just give it a quick clean up, any unnecessary files removed (even like word documents and batches of unused images), it helped my laptop a Ton.
does it still work? or does it just crash upon startup? if it doesn't then try using not windows 7/8 but 'safe' mode version of windows if I am right.
If you ever use you laptop for gaming I know that slows it down a lot, maybe uninstall some games. I'm sure you have alread thought of this, just simply saying suggestions that might help. My laptop used to have STEAM and everytime it updated or automatically run it would stall my laptop so that it would literally take from 30 minutes to 1 hour. As for virus's 'malware bytes' is free and works like a charm. however im guessing it is just a fault with your hardware which otherwise can't help. Ignore this if i'm being too technical
(or rather not technical enough). I was lucky to have mine fixed by a friend of my mum and have it repaired cheaply and reliably, i would recommend this solution if you trust any local friends who have the knowledge.