Each approach has its own associated cost and benefits, with each being suited to certain types of faults.
The first method you could try involves removing the internal hard drive, installing it in an external HDD case and attempting to read the contents via a second computer.
These type of external drive casing devices are widely available in computer peripheral shops. They are often used by people who wish to swap their existing drive for a new one, and still get some use from the old drive as an external storage device.
However, if your drive crashes then these cases can become useful for extracting the drive and attempting to read it via a second computer.
The second method does not require you to open up the computer or interfere with the hard drive. This approach involves booting your computer from a Linux CD. You could download the Linux Live CD (from a second PC), burn it to CD and insert it in your damaged computer.
You then modify your BIOS settings so that the computer boots from the CD as first priority. When you restart the PC, the BIOS will use the Linux operating system off of the CD to start up the operating system. This does not affect Windows. You can then simply copy the disks contents to CD/HDD.
The final method is to use data recovery software to attempt to scan and analyze the data clusters on the disk and retrieve your lost documents. This type of PC repair and maintenance does not attempt to fix the cause of the fault, but can result in you being able to salvage your files.
If you are still unable to recover lost files after trying out these approaches then you should seek out the help of a PC repair shop or a PC technician to complete the repairs or data recovery.