Hi all,

i have a problem with my acer laptop

acer Aspire 4720z Series model no : (201)

It works well, but before the welcome message appears shows a black screen and written on it Operating System not Found!

knowing that my brother was working on a good, but he has removed the battery and the system works

so plzzz dears if you have any idea tell me becouse it made me crazy !

shows a black screen and written on it Operating System not Found!

That is an indication that the BIOS was unable to pass control to an operating system on any of the boot devices listed in the CMOS setup.

but he has removed the battery and the system works

I dont understand. You mean that when the battery is removed, the system works? How is that possible?

I would guess that the battery was removed long enough for the CMOS/BIOS to reset to factory defaults.

my brother has been removed the battery during operation of the device,and then When he tried again to re-run the laptop it shows him a black screen written on it "operating system not found "!

guys please i need a hlep, and thanks all

Which Operating System?

Have a quick look in the CD/DVD drive and take out any discs, disconnect any external drives connected directly to the computer, try booting again. Work?

Next, please go into your BIOS and check that the Boot sequence is correct, make the CD the first in the Boot sequence and then the hard disk as second. (This sequence is important for further steps if necessary) Save those settings and reboot.

Now we need to know which Operating System and whether you have the Disc for it. If you don't then there are other ways of fixing your Master Boot Record. (MBR) It would be very good if you could download UBCD and write it to a disc.

Let us know when you're ready, tell us which OS, and we'll walk you through the rest of the way.

Sorry, please read my post above and if necessary you can download the UBCD here. (I forgot to include the link)

is there anything can help me by useing F12 whene the computer starting ?

thanks guys

guys if u need anything to help u i can write all the messages that appears on the black screen

tell me and i am ready !

to bigPaw,

dear it is already saved as IDE CD first and IDE HDD as Second !

i did not made any change on the boot sequence

what about the next step dear??

Here are All the messages that appear on the screen black :

Broadcom UNDI PXE-2.1 v9.4.5
Copyright (C) 2000-2006 Broadcom Corporation
Copyright (C) 1997-2000 Intel Corporation
All rights reserved
PXE-E61: Media test failure,check cable
PXE-M0F: Exiting Broadcom PXE ROM.
Operating system not found

Here are All the messages that appear on the screen black :
Broadcom UNDI PXE-2.1 v9.4.5
Copyright (C) 2000-2006 Broadcom Corporation
Copyright (C) 1997-2000 Intel Corporation
All rights reserved
PXE-E61: Media test failure,check cable
PXE-M0F: Exiting Broadcom PXE ROM.
Operating system not found

that looks like "boot to network" is enabled in the bios ,you need to go into the bios and find it and disable it

dear caperjack,

i went to the bios settings and i disabled it , then the laptop restart, now it is appears a black screen with one message "operating system not found "!

i think that i will be crazy,what's going on dearrrr ?!!!!!

heeeeeeelpppp

i went to the bios settings and i disabled it , then the laptop restart, now it is appears a black screen with one message "operating system not found "!

in the bios make sure you harddrive is shown as first choice in the boot options ,if its not showing in the bios then you have a bad harddrive

It's most likely that the hard drive has had it. It's simple, buy a new hard drive and install windows from a cd onto it. If you don't have a windows cd then you will have to buy that too.

the hard drive is the first choice already dear !

Does that mean you have tested the hard drive and found it to be working perfectly with no bad sectors?

the hard drive is the first choice already dear !

so it the first in the list and still not booting to it ,then its highly likely you have a bad harddrive ,Dear

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