Can I uninstall Windows 7 and roll back to XP?

Can I uninstall Windows 7 and roll back to XP? Or, do you have to reinstall Windows XP completely?

There is no easy way to uninstall the operating system, but by performing the following steps, you can manually restore your computer to the previous operating system. These steps also apply to restoring your computer back to Windows http://www.aliyun.com/zixun/aggregation/15470.html ">vista." Reinstalling the previous operating system is easier than performing the following steps. Only advanced users are advised to try these steps.

Step 1: Determine if the Windows.old folder exists and if there is enough free space on the Windows hard drive

1. Click the Start button, and then click Computer.
2. On the View menu, click Details.

3. In the Free Space column, note the amount of free space in the local disk (C:) below the hard drive area.
4. In the hard drive area, double-click Local Disk (C:), and then determine if the Windows.old folder exists.
Important: If the Windows.old folder does not exist, you cannot restore the previous Windows installation to this computer by following the steps in this article. You must back up and restore your files, or transfer your files to the previous operating system.
5. Right-click the "Windows.old" folder.
6. Windows 7 Determines the size of this folder after a few seconds.
Determine if the size of the Windows.old folder is less than the available space for local disk (C:) that you saw in step 1.2.
Note: If the size of the Windows.old folder is twice times the free space of the local disk (C:) item, you may not be able to restore the previous Windows installation.

Step 2: Start the Windows recovery Environment

1. Put the Windows 7 installation disc into your DVD drive, and then restart your computer.
2. Press a key at System prompt to reboot from CD.
3. In the Install Windows window, select the language, time, currency, keyboard input method, or other input method, and then click Next.
4. In the Install Windows window, click Repair Computer.
5. In the System Recovery Options window, click the version of the Windows 7 operating system that you want to repair, and then click Next.
6. In the System Recovery Options window, click Command Prompt.
A command Prompt window opens with a command prompt displayed. You can type the command described in the following steps at a command prompt.

Step 3: Rename the Windows 7 folder

Note: In the following steps, if you type one or more commands at a command prompt, and then press Enter, you may receive the following message:
The system cannot find the specified file
If you receive this message, go to the next step in this section, and then type the commands in the step.
At the command prompt, type the following command:
1. Type the following command, and then press Enter:
C:
2. Type the following command, and then press Enter:
ren Windows windows.7
3. Type the following command, and then press Enter:
ren "program Files", "program files.7"
4. Type the following command, and then press Enter:
ren "Users" "users.7"
5. Type the following command, and then press Enter:
ren "Documents and Settings" "Documents and Settings.7"

Step 4: Copy or move the contents of the Windows.old folder

Note: In the following steps, if you type one or more commands at a command prompt, and then press Enter, you may receive the following message:
The system cannot find the specified file.
If you receive this message, go to the next step in this section, and then type the commands in the step.
At the command prompt, type the following command:
1. Type the following command, and then press Enter:
move/y c:\windows.old\windows C:\
2. Type the following command, and then press Enter:
move/y "C:\windows.old\program Files" C:\
3. Type the following command, and then press Enter:
move/y c:\windows.old\users C:\
4. Type the following command, and then press Enter:
Move/y "c:\windows.old\documents and Settings" C:\

Step 5: Restore the boot sector of the previous Windows installation

Type one of the following commands at the command prompt, depending on your situation.
Note: In the following command, D: Represents the DVD drive. If the DVD drive on your computer is represented by a different drive letter, such as E:, use the drive letter in the command.
• If the previous Windows installation is Windows XP
Type the following command, and then press Enter:
D:\boot\bootsect/nt52 C:
• If the previous Windows installation is Windows Vista
Type the following command, and then press Enter:
D:\boot\bootsect/nt60 C:

Step 6: Restore the Boot.ini files from previous Windows XP installations

Note: Follow these steps only if the previous installation is Windows XP.
At the command prompt, type the following command:
1. Type the following command, and then press Enter:
C:
2. Type the following command, and then press Enter:
attrib boot.ini.saved-s-h-r
3. Type the following command, and then press Enter:
ren "boot.ini.saved" "Boot.ini"
4. Type the following command, and then press Enter:
attrib Boot.ini +s panes R

Step 7: Close the Command Prompt window, and then click Restart.

1. At the command prompt, type the following command, and then press Enter:
Exit
Click Restart to restart the computer