1. Try boot from CD or USB. There are rescue CD/USBs to boot and access your file system, for example http://www.sysresccd.org/Main_Page
2. If the CD or USB doesn't boot your computer, take out the hard disk drive and put it in a disk enclosure. You can read the disk from another computer.
Here is my Dell experience: H for home, O for office use
Desktop:
H - Dimension 2005, still working, but I replaced RAM, disk, CMOS battery, DVD drive.
O - Poweredge 2006, died within 1 year, and was fixed after replacing the motherboard.
O - Poweredge 2007, still working.
O - Vostro 2009, still working.
H - Dimension 2011, "dead on arrival". Actually it shut down itself everytime I ran CPU burn, otherwise fine.
Laptop:
H - Inspiron 2006, still working, RAM upgraded.
H - Inspiron 2007, still working, RAM upgraded. Battery only lasts 20 minitues.
