As both hard drives are experiencing errors it could be that both are faulty or as you said above something else.

You said that sometimes both are not recognised when you first start the PC which makes me think it could be a power supply, motherboard or cable problem. Have you tried changing the cables? What model are the hard drives. You can download diagnostic tools from the manufacturers to test them, you may have to download at a friends house if you don't have internet. Please post back if need help with this.

As for backing up your data that would be a good thing. If you have a DVD burner then maybe back your files up to DVD, however I don't recommend doing it this way. Otherwise you could buy another hard drive and put that in the pc to move the data across or get an external hdd.

ill try using different cables. about backing up, my second drive is western digital and came with tools, i guess ill have to back up on cds since i cant afford a hdd. ill be back with details.