EDIT: NVM Everyone, I downloaded a custom theme- all is well now. Windows themes caused it

Thanks for everyones help though!
Hey there everyone!
Newbie here, not only to the forum but to W7 as well

I wasn't sure whether to post this in Customization or Support, but I need the support so here it is!
I just want to clear something up first: i know how to change themes, but changing them makes no difference to the problem. I can't read anything because of the colours of the text and BG, this will make more sense:
I've been in advanced settings too but nothing changes it! Please, I really need to sort this out, I can't read anything!
Thanks all!