ACER aspire 5553g Cannot find operating system. Boot menu doesnt show hardrive and erecovery crashed

Hi - my ACER aspire cannot find the operating system and when i go to the bios it does not show the hard drives. When i went to F12 instead of F2 i could see the Toshiba HDD name. Then went to F10 to get to erecovery, but on loading it crashed with an error and now when i go to F12 i can no longer see the Hard drive.

I have included the detailed account of what i have done below but i am thinking now that i should just reinstall the whole lot. However i can no longer get to erecovery and the WD external hardrive i had backed up to was stollen a while ago and stupidly i didnt re do the back up.

So i cant reinstall to factory settings. Can i get a disk from Acer that will have the original factory settings including the Window 7. Thats what was on it before ?

Here is the detail with the error messages and everything

--------- I have an acer 5553g laptop. Used mainly for internet, few presentations, a few pics and to link with tablet.. like drop box, google + . i player.. that sort of thing but not overused. Its 2 years old.

I have Never dropped it and been extra carefull with it.

On Sunday it appeared to die. what i mean by this is that i could not find the operating system nor the hard drive although i can still access BIOS by pressing f2 or multi bios by pressing F12.

This is the message

INTEL UNDI PXE-2.0 (build 083)
Copyright (c) 1997-2000 intel coporation

FOR ATHEROS PCIE ETHERNET CONTROLLER V2.0.1.9 (12/15/09)

CHECK CABLE CONNECTION !
PXE-MOF: EXITING INTEL PXE ROM
OPERATING SYSTEM NOT FOUND

This is what i have done so far. At first a couple of times it did go automatically to system repair which i left on overnight the first time. This did not work nor did it worked the second time. After that it did not come up automatically.

I went to the F2 Bios screen and noted that my IDEO model name and serial number were not shown just the HDD but no name.

Next night i manually opened the CD tray and put a copy of windows 7 in so that i could use repair from disk.
i went to F2 and changed the BIOS to point to the CD.
This did fire up but running the repair didnt work tried several times, a message came up asking if i had recently installed any hardware (which i had not) then said something about contacting manufacturer or administrator.
The memory check and other options didnt work... i di have a change to attempt to copy boot drives .. but when i accessed the folders from the disk i didnt know what i was looking for really.

I changed the bios back . Next night after reading more on line in the day I pressed F12 before to make sure the BIOS was pointing to harddrive and at that point i could see the toshiba hardrive name and the model number so i thought great i have a chance. It did not display on the F2. I tried this so that i could try to access the partition that had some acer recovery utilities.
The title at the top was Phoenix securecor(tm) set up utility

When i exited I got the same messages as before.. check cable etc

So i then decided to start up again pressing alt F10 a number of times to try to get to the erecovery. It did start up and I thought i has a chance to recover everything... i waited in anticipation for 30 mins.

Then another error message :

NAPP-KM:NAPP7.exe - Application error
The exception unknown software exception (0x000000d) (exact words)
occured in the application at 0x1005a6d8
click ok to terminate the programe

The ring cursor was still spinning but no hard drive light anymore so i waited 20mins then pressed cancel

Upon starting the laptop again i went to both F2 and F12 and this time i found that the IDEO Model name and Serial number in F12 had disapeared. 

(i have been told that some viruses if bad can stop your Bios seeing the zero sector could this be it ?)

I am now completely at a loss.

Do i simply just buy a new harddrive and start again, bearing in mind that windows 7 was preloaded by Acer Or is there another few things i could try ? Given that this week was already a bit of a learning curve.. simple solutions or in lamen terms would be good... or if it is technical.. step by step.. i may know a little bit but not enough