if your hdd is actually dying, if you delete everything on it, you will release all the bad sectors and problems will came back once you overwrite them...
i once had a discussion of what to do with corrupted files with a google engineer and the conclusion was to leave them there 😛
now, the problem is mainly using firefox and youtube, which both create a lot of temporary files... and windows is usually configured to write them to the hdd
so if you wanna try something temporary, after you backed up all your important files (in case the hdd fails definatevely at some random point), go to control panel, system, advanced system settings.
Then go to settings in performance, and in the advanced tab disable the pagefile.
And after that go back to adv. sys settings and go to environment variables. I'm assuming you have 2 partitions on the hdd, since asus ship the notebooks like that, change the variables location of TEMP and TMP (for both user & system variables) to folders you will need to create previously on the second partition.
Once you done both you will now be using the ram and a new part of the hdd to manage temporary files, which may temporary solve the errors you are facing...
hdd's are really cheap nowadays, ssd's are getting there as well :p, the best thing you can do is getting a new one, perhaps you can avoid this for a few months if you manage to make your system stable again, but it will get slower, files will get corrupted, and at some point the hdd will fail for good...
i'm not really sure asus policy regarding hdd's, but i wouldn't get my hopes up, because in the user manual it states that the hdd is one of the parts, if not the only, that will brake, so i'm not sure they will cover it...
i've broken 4 hdd's over the past 7 years with different notebooks... i've learned a few things after that... one is not to move the notebook much if the hdd is writing stuff, the other is to stay away of seagate hdd's (some people may like them, i don't wanna start a flame war, but i found that they are more fragile than the competition drives...)