i have no money to pay for one..is there one thats completely free?

I know I can’t upgrade because I don’t have Vista. I’m a student and can get Windows 7 for a reduced price and would like to do that. but I don’t want to waste my money if I can’t do a full install with the upgrade disk.

i want to buy it, but is it worth the money? What’s the summary of the series and what would you grade it?

I got a link to regcure…it scanned and downloaded for free but wants money to fix errors…any totally frree ones out there? My computer is running/booting so slow and crappy this is frustrating…IF there are NO free registry cleaners please advise me of a good one that is not BS…you know, one that is SAFE to give money too and does its job well
I do use malewarebytes anti-maleware
Spybot S&D

what is a good registry cleaner and a good cpu/ram diagnostic/cleaner programs. Microsoft uses "uniblue" i believe and its like a program. I can’t afford that. there has to be a good/decent free one until I get the money for a "certified" program, lol. Any help at all will be greatly appreciated