uninstall ubuntu

http://www.users.bigpond.net.au/hermanzone/p18.htm

这个网站告诉了你至少6种方法删除linux————当你得PC是windows&linux双系统的情况下.
我喜欢最后一种：Mbrfix.exe

http://www.sysint.no/en/Download.aspx

这是个windows工具,你可以轻松的修复你的MBR。

MbrFix.exe

MbrFix.exe is a useful tool for professionals or serious
hobbyists, it has been updated to work for Vista as well. It can do a
whole list of other neat operations as well.

1) Download a small utility called MbrFix.exe here, http://www.sysint.no/en/Download.aspx
Read all about MbrFix.exe here, http://www.sysint.no/nedlasting/mbrfix.htm

2) Paste the file to the root of drive C:

If you don't know what I mean by 'the root of drive C, just open in 'My
Computer, Click on Local Disk (C:), open it, and paste MbrFix.exe.there.

3) Click 'Start'->;'Run', type CMD (for a Command Prompt).

The command prompt will at first be something like,

(Where 'Herman' is my username for Windows, yours will probably be something different).

Change it to just a C: prompt by typing: cd \ , then press 'Enter'.

After that you should just have a plain C:\>

Type this command after the C:\>: MbrFix /drive 0 fixmbr /yes
for example,

Nothing much will appear to happen, your monitor may blink slightly,
that's all. You will see the plain C:\> again. Type 'exit'.

4) That's it! Reboot to see if it worked.