|Describe what your situation is, the more you tell us the better.|
Tell us the make and model of your brand name system, or if you have a generic desktop system, the make and model of the mboard.
The specific model of a brand name system is shown on a label on the outside of the case somewhere, or it can often be determined by going to the brand name's web site and loading a program they have available.
For Dell computers, they have a Service Tag number - the specific model can be determined by using that on their site, or can often be determined there automatically by you downloading some software. The Service Tag number should be on a label on the outside of the case, probably on the bottom on a laptop, on the back on a desktop, and is often also shown in the bios Setup.
The model, sometimes the make, of a mboard in a generic desktop system is usually printed on the mboard's surface in obvious larger characters, often between the slots.
Does the computer boot (start up) ?
If so, do you have video before the operating system loads ?
If not, that doesn't necessarily indicate your personal files are gone.
If it does boot, and if you have video before the operating system loads, is your problem the operating system won't load properly ?
If so, your personal photo and music files etc. are probably still there, if there's nothing physically or logically wrong with the hard drive(s) itself (themselves).
The personal files you don't want to lose can be copied to elsewhere if necessary, one way or another.