Removing Windows 7 and Going back to XP

simontompkins

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Jul 12, 2006
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Since this is a long post please note that I have now solved the problem.


I've written the information below as I think it might be useful if people are thinking of ditching windows 7 or have windows 7 and XP on a dual boot system. I was in a worl of pain on this problem and I hope I can save some people the same kind of pain.




I set up Windows 7 on a virtual drive on my second hard drive.
I then installed W 7 from an iso image and ran W 7 from the virtual drive.
Since W7 was the release candidate and it had some problems I wanted to stick to XP.

So at this point I'm running a dual boot system

This is what I think caused the problem:

I had a boot loader which I think was Windows 7 boot loader. The (I think) W7 boot loader asks me if I want to load W7 or "earlier operating systems" So I then choose "earlier operating systems and the I choose my working XP version. (In fact I had two XP pro's running but only one would actually load.

So I chose the XP version I knew would load and then ran XP fine.

Now at this point I want to speculate on what caused all the problems.

Hard Drive 2 contained the W7 Boot loader. Hard Drive 2 is also the bootable drive so it has to go through HD2 before it can run the XP on Hard Drive One.

What I did was remove Hard Drive 2. Did a full format on Hard Drive 1 and then asked XP pro to install. All seemed fine, copied files across. However on the first boot up of XP, immediately after the Microsoft Logo I got a: "your bios does not support ACPI" message.

This is a pig of a message. What was some help was the fact that I'd installed exactly this hard drive and exactly the same hardware on at least half a dozen times. So something must have changed somewhere. Microsoft knowledge base was typically unhelpful. As wioth many problems it assumes that it the problem. In this case a Bios fix is the suggestion. However, any given Bios may not neecesarily solve the ACPI problem. You'd have thought that the latest Bios would be the one to go for but it seems taht with this particular problem that is not neccesarily the case. Sometimes it's better to choose an older Bios.

Looking in the Bios itself you can disable ACPI. Also pressing (I think) f5 at "install storage drivers" bypasses the ACPI routine and is supposed to in many cases solve the problem. However, pressing F5 (or F6 can't remember which one was suggested) doesn;t tell yhou that the Bios or the new operating system is bypassing it. According to micrososoft it happens even though you don;t get a confirmation message.

So reset the Bios back to default. Swapped hard drives, SATA cables. Formatted the hard drives with Sea Tools just in case the XP install was leaving bad files behind (Never quick format if you have to reinstall over a new install that goes wrong - when you reinstall again - on a quick format the "new" install sees the files on the hard drives and if the install went wrong the first time - the left behind bad files invariablty caused the same problem again.

All to no avail. Thought maybe my slipstreamed copy of XP pro with service Pack 3 was the problem so tried a bog standard XP pro. All to no avail. At this point the BIOS stopped seeing the hard drive altogether and I went to bed amid all the confusion.

So it seemed to me that there was some low level conversation between the operating system and the Bios and the PC. So I thought that maybe a different version of Xp would have a different conversation and maybe install over the problem or solve the issue.

So I tried XP Media Center and it all went fine. Oddlly when it loaded first time I had a dual boot loader witrh two versions of XP. Probably because I after so many attempts I was almost giving up and just before the last instal had a quick format rather than a full format.


However this is what I think caused all the problems:

Windows 7 has it's own boot loader. Now to those of use whove run dual OS setups under XP you just change the boot option in the boot.ini file and delete whichever option you don't want.

However and this is the point. I think that Windows 7 boot loader is much more than XP boot loader. When I failed at my install after deleting Windows 7 and the removing the second hard drive I think (and I do mean think) that the ACPI problem is caused by not removing windows 7 properly. I've alwasy thought that there were essentially two seperate things on an install the BIOS and the operating system. ACPI, if I understand correctly is concerned with with what's called the HAL or Hardware Abstraction Layer. This sits in between the BIOS and the OS. Now (again I believe) that Windows 7 alters the HAL. It communicates with the HAL on install and understand how it works.

When you simply delete Windows 7 you leave all the Windows 7 setting that work at this level and earlier operating systems have no idea how to communicate with the Bios OS and HAl properly. You can't (I believe) just format the hard drive and install an earlier operating system because there's information that the older XP can't understand or at least solve.


The lesson in all of this is never simply just delete windows 7 and think that an earlier operating system will install. I remember that you're advised to stick in Windows 7 and get windows 7 to clean up:

This is one link

http://support.microsoft.com/kb/971760/

I'm posting this is the hope that other people benefit from my experience. I've seen other answers on forums where people suggest just deleting formatting and installing XP. Please don;t do it. I know it worked in the past but I really feel that not allowing windows 7 to remove itself caused all the problems. By the way it screwed with two hard drives. I tried to format the second hard drive but I couldn;t get anything form either hard drive. So I think Windows 7 can effect an hard drive that it's involved with. As I said even a format with sea tools failed to get the PC to see the hard drive and I think that I only succeeded with Media Center because it was slightly newer than XP.

In any case hope the above information is useful to someone and stops people going through the pain that I went through.
 
XP does not contain drivers for AHCI mode. You must put them on floppy, or a thumb drive, and use the "F6" feature to load the drivers when prompted, or XP will not be able to see or detect you hard drive. Either you supply the correct drivers, or you set the SATA mode to IDE mode.
 

LePhuronn

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Apr 20, 2007
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OK here's one for you then:

I have Windows 7 RC on a Sempron laptop - was running wonderfully but of course now it's expired, so I'm going back to Windows XP Home.

I put my XP Home disc in the drive, boot from it and without fail as it starts to load the initial set of files into memory some of these files will report as being corrupted.

I don't even get as far as the actual setup.

I've tried this with 5 different XP Home discs, yet the drive reads other data and video discs fine with no issues.

What ya reckon to that?
 



Perhaps you have burned 5 illegal copies of XP home from a bad disk?
 
G

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It is likely that few will experience your dual boot problems because most are doing a clean install of Windows 7 alone. There is very little if no need for XP for Dual Core systems. If you have a dual core processor Windows 7 will run better than XP and will also run the majority of XP applications.