原因：更改了jdk安装版本
方法：修改netbeans安装目录下ect下netbeans文件，
详细代码位置：
# Default location of JDK:
# (set by installer or commented out if launcher should decide)
#
# It can be overridden on command line by using --jdkhome <dir>
# Be careful when changing jdkhome.
# There are two NetBeans launchers for Windows (32-bit and 64-bit) and
# installer points to one of those in the NetBeans application shortcut
# based on the Java version selected at installation time.
#
netbeans_jdkhome="C:Program FilesJavajdk1.7.0_67"//在此处修改，把你jdk安装目录复制到此处
# Additional module clusters:
# using ${path.separator} (';' on Windows or ':' on Unix):
#
#netbeans_extraclusters="/absolute/path/to/cluster1:/absolute/path/to/cluster2"