turn on your computer press F2 goto your BIOS 

Than goto Advance Select ATA Instead Of AHCPI Save the setting then try to reboot Your Win 7

hope this will work .

There is no such terminology as AHCPI

AHCI has to do with SATA hard drives.

ACPI has to do with BIOS.  It is possible to have NON ACPI compliant Bios.

STOP: 0x000000A5 (Parameter1, Parameter2, Parameter3, Parameter4)
The ACPI Bios in this system is not fully compliant to the specification.

Please read the Readme.txt for possible workarounds, or contact your system vendor for an updated bios.

To resolve this behavior, contact the manufacturer of your computer to obtain a BIOS that is fully ACPI compliant.

To work around this behavior, manually install the Standard PC hardware abstraction layer (HAL):

1. Restart the computer to restart Setup.
2. When Setup starts again, press F7 (not F6) when you see the "Press F6 if you need to install a third-party SCSI or RAID driver" screen.

Windows automatically disables the installation of the ACPI HAL and installs the Standard PC HAL.

Hey guys. I have Dell inspiron N4050, I was attempting to install a fresh copy of Windows 7 Ultimate and after installation, it restarted I get an error blue screen that reads: A problem has been detected and windows has been shut down to prevent damage to your computer. If this is the first time you've seen this stop error screen, restart your computer. If this screen appears again, follow these steps: The BIOS in this system is not fully ACPI compliant. Please contact your system vendor for an updated BIOS. Technical information:

 now when i turn on my laptop it is not displaying please tell me how i solve my problem? 

                         help me!!!!!!!!!!! 

this is the same issue with every one but this is my personal experience i did windows 7 Enterprises and i dint get any blue screen like am getting it before and it runs greatly in my N4050. you must try this. and keep one thing in mind this is not a hardware issue.

this is the same issue with every one but this is my personal experience i did windows 7 Enterprises and i dint get any blue screen like am getting it before and it runs greatly in my N4050. you must try this.

I have spent much time on installation Win 7 (Pro / Ultimate / Home) with same error again & again.

Now I will try Win 7 Ent on my Dell Laptop to see if it works

Well well well , excuse me mr. wharever speed step u are , first of all i gotta tell u that Schaibeez is facing issue with a system rubnning windows 7 and not windows XP , and the ACPI technology which is being reffered here and not DELL specific technology , well let me brush up your rotten mind , ACPI technology was launched in year 1996 , where it means Advance Controller power interface , where System BIOS has the ability to share power settings withe the installed OS , but there are scnerios where if the BIOS is not of the same level top share the ACPI settings to the Operating system , may be just because if teh power settings which the Operating system demands are of the higher hierarchy , then a user will face this issue. But there are even certain starnge scnerios where a user is confused that the system running absolutely fine for a few months and all of a sudden the same settings which were there before and were successfully able to share power settings from BIOS , just stops sharing it ..... the reason behind it is that the Level of the ACPI hierarchy  increases eventually depending upon the period of windows updates done , All windows updates are not responsible for ACPI .. but there are only limited and few updates which , if , unfortunately gets inside the system it actually increase the hierarchical level of of the ACPI input required by the OS to even start and thes when user starts getting ths error mesage. and the worst part is that even if the USer will try to reinstall Operating system and start from teh scratch it wont proove to be of any help. because once the Updates are done , then those probably corrupt the ACPI compliant of teh bios.. OR are directly present in the cache memory which is not relarte to hard drive offcoure.

There is work around solution for this issue. Try to install lower version of Operating system in rthe same machine Schaibeez  apart from the version which were installed before , because power requirment settings for all operating systems are different. for example you can try to install Windows 7 home basic or windows 7 starter just for time being. and once you are done , you just have to update the BIOS of your machine . download the latest BIOS update from Dell official Website. and then if you wish you can install Windows 7 ultimate ort any other later versions.

And yopu Mr Speedy ,Yes i am not a Dell user But I am a DELL Employee. .... MIND IT