Operating System not found

In febuary of last year i spent a hefty £1100 on my laptop and it had worked find up till April this year where characters had begun to appear on the screen and strange lines. this problem got worse and worse and eventually i gave up and put it away thinking i would get it sorted later. recently i have thought it to be a driver problem and have set about trying to update my driver for my GeForce Nvidia 8600 GS card but no luck i even tried uninstalling it and then reinstalling it but still no luck. so i then decided it was the graphics card its self that was the problem. the laptop being out of warranty anyway i decided to remove the back to see if the card was fixed i removed several conpoments including my hard drive. i could not see the graphics card as i did not have the right tools to completely remove the back. so i reasembled everything and turned on my laptop only to find.....

Operating system not found

and now i have no idea what to doo please help.

It may your HD is not connected properly - suggest you check the connections.

Do you have any kind of install/recovery disc?

Try booting it and see if it has recovery options - Startup repair for example.

http://www.vistax64.com/tutorials/194765-system-recovery-options.html

As a Tech myself,may I suggest you take it to your nearest trusted Tech before doing anything more? If you totally stuff things up,guess who will be paying?My best advice...pay only once..to someone qualified and knowledgeable enough to not only fix it but guarantee the work. Believe me,it will be worth it.

Hmmmmmm i may try that it would be better to get the whole thing fixed problem is if the graphics card is fused to the mother board then i will have to teplace that. anyone know if the sony Viao Vgn-fz21z has a replaceable graphics card? also how hard would it be to check the hard drive cables mine doesnt seem to have any its just a sliding sort of mechanisum.