安装PIL库的时候，直接提示：Python version 2.7 required, which was not found in the registry。
如图：

大意是说找不到注册表，网上搜索解决方案。

新建一个register.py文件写入代码：

复制代码 代码如下:
import sys
  
from _winreg import *
  
# tweak as necessary
version = sys.version[:3]
installpath = sys.prefix
  
regpath = "SOFTWARE\\Python\\Pythoncore\\%s\\" % (version)
installkey = "InstallPath"
pythonkey = "PythonPath"
pythonpath = "%s;%s\\Lib\\;%s\\DLLs\\" % (
    installpath, installpath, installpath
)
  
def RegisterPy():
    try:
        reg = OpenKey(HKEY_CURRENT_USER, regpath)
    except EnvironmentError as e:
        try:
            reg = CreateKey(HKEY_CURRENT_USER, regpath)
            SetValue(reg, installkey, REG_SZ, installpath)
            SetValue(reg, pythonkey, REG_SZ, pythonpath)
            CloseKey(reg)
        except:
            print "*** Unable to register!"
            return
        print "--- Python", version, "is now registered!"
        return
    if (QueryValue(reg, installkey) == installpath and
        QueryValue(reg, pythonkey) == pythonpath):
        CloseKey(reg)
        print "=== Python", version, "is already registered!"
        return
    CloseKey(reg)
    print "*** Unable to register!"
    print "*** You probably have another Python installation!"

启动命令切到register.py文件目录下执行:

重新安装PIL，错误解决，安装成功。

如果是win7 64位的用户在安装Python 32位程序时，如果选择只为当前用户，以上问题不会出现。如果选择所有用户，就试着使用以上方法解决。

提示其它版本解决方法类似。