IMac running slowly

Question

I own a late 2010 iMac. I understand it's old but I do not believe it should be running as slowly as it is. I've tried everything to fix it. I ran Mavericks since it came out and haven't had issues since a few days ago. I ran Disk repair and it told me something was wrong and wasn't able to fix it. It told me to restore and erase the computer. I did so and still slow and unresponsive. Boot time takes forever. Is there anything I can do without bringing it to apple? The warranty is way outdated and I don't have the money to replace the hard drive.
Again, the iMac is completely erased so their should't be any issues. Please help

Answer 1

If Disk Utility found a problem and was unable to repair it in Recovery mode, then the hard drive is failing or there is some other hardware fault. The fault must be repaired if you want to continue using the machine. Alternatively, you may be able to start up from an external drive and stop using the internal one.
Make a "Genius" appointment at an Apple Store, or go to another authorized service provider.
Back up all data on the internal drive(s) before you hand over your computer to anyone. There are ways to back up a computer that isn't fully functional—ask if you need guidance.
If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.
Keeping your confidential data secure during hardware repair
Apple also recommends that you deauthorize a device in the iTunes Store before having it serviced.
*An SSD doesn't need to be zeroed.