Repair or replace hard disk alert message

I'm getting an alert saying that I need to repair or replace my hard disk and back up my laptop. I've already backed it up. My computer has been having some issues. I thought it was something I could fix myself. I had gotten a kernal_data_inpage_error a few times and I thought chkdsk had repaired it then I started to get the hard disk error. Sometimes my computer works fine and sometimes it's practically useless it goes so slow. Since I started getting the hard disk issue my computer has been running smoothly. Smoother then it usually does. What's up with that? I need this for work. Will it hurt anything if I keep using it as long as it's still running and then when it finally dies just replace the hard drive? I was thinking about replacing the hard drive anyways to have more space on my computer. Also, could the warning be a false alarm and I might could fix it myself? My laptop is made very weird and the whole stinking laptop has to be disassembled to swap out the hard drive unlike my old laptop where you can just unscrew the bottom and bam there everything is. I just don't want to spend money on doing computer repairs I could fix myself.