Windows 7: System Repair not working!

You may have messed up your computer running a registry cleaner which are almost all sales scams. None are really recommended by MS and certainly not by anyone here.

You can back up your files and consider running Factory REcovery from Windows 7 using the link I sent you, after making your Recovery Disks so you have an alternate method.

so i take it as never use a registry cleaner since they're not safe and effective?

Yes. CCleaner has a Registry tab on it which many use safely, but others don't recommend even that.

Are you going to run Factory Recovery? Acer Support: Frequently Asked Questions list for Recovery media and Restoring a system to factory load

The other option is to clean reinstall using a Windows 7 retail installer for your version, using the Product Key on COA sticker on machine. Read about it here: Reinstalling Windows 7

yes i checked and i already have the factory recovery disks since i created them before but they'll make me lose all my data i think, wont they? well my windows is genuine and yes i can see the sticker too but i didnt get a windows DVD*they dont give those out anymore , right? gone are the days of XP* with my laptop and a new one will cost too much. i do have cccleaner and i guess i'll use only that from now on

You'll need to backup your data first before Factory Recovery. Even though you have the disks, run it from Windows using the PQService partition as given in the tutorial, save the disks as a backup method since either can fail.

You can borrow or find a Windows 7 retail installer, unlock if necessary, or download from the web from Digital Life's official Windows 7 downloads.