安装 MyEclipse 时出现 An error occurred while copying software to your machine 字样，有部分文章提出可能是因为之前安装没有完全卸载。比如 MyEclipse（不论版本是啥）卸载后重新安装，提示：拷贝到计算机时出错；问题解决方案：。
今天我也遇到了这种问题，但是用这种方法没有成功。
然后我查看了错误日志：
++ ERROR #1
Status ERROR: org.eclipse.equinox.p2.engine code=4 An error occurred while collecting items to be installed null children=[Status ERROR: org.eclipse.equinox.p2.engine code=0 session context was:(profile=com.genuitec.delivery.package.profile.2915-Enr-0574, phase=com.genuitec.pulse.installer.processor.offline.copybundled.CopyBundledCollect, operand=, action=). null Status ERROR: org.eclipse.equinox.p2.engine code=0 java/util/jar/Pack200 java.lang.NoClassDefFoundError: java/util/jar/Pack200]
Status ERROR: org.eclipse.equinox.p2.engine code=0 session context was:(profile=com.genuitec.delivery.package.profile.2915-Enr-0574, phase=com.genuitec.pulse.installer.processor.offline.copybundled.CopyBundledCollect, operand=, action=). null
Status ERROR: org.eclipse.equinox.p2.engine code=0 java/util/jar/Pack200 java.lang.NoClassDefFoundError: java/util/jar/Pack200
java.lang.NoClassDefFoundError: java/util/jar/Pack200
at com.genuitec.pulse.installer.processor.offline.copybundled.CopyBundledCollect.transferPackedArtifact(Unknown Source)
at com.genuitec.pulse.installer.processor.offline.copybundled.CopyBundledCollect.transferSingle(Unknown Source)
at com.genuitec.pulse.installer.processor.offline.copybundled.CopyBundledCollect.completePhase(Unknown Source)
at org.eclipse.equinox.internal.p2.engine.Phase.postPerform(Phase.java:251)
at org.eclipse.equinox.internal.p2.engine.Phase.perform(Phase.java:101)
at org.eclipse.equinox.internal.p2.engine.PhaseSet.perform(PhaseSet.java:47)
at org.eclipse.equinox.internal.p2.engine.Engine.perform(Engine.java:75)
at org.eclipse.equinox.internal.p2.engine.Engine.perform(Engine.java:44)
at com.genuitec.pulse2.client.common.eclipseaccess.InterceptingEngine.perform(Unknown Source)
at com.genuitec.pulse.installer.processor.offline.copybundled.CopyBundledArtifactsProcessor.runWithErrorHandling(Unknown Source)
at com.genuitec.pulse.installer.processor.ProcessorWithFatalErrorHandling.run(Unknown Source)
at com.genuitec.pulse.installer.module.ui.progress.GenericProgressPage$GenericProgressJob.runProgressWithCancelBlocking(Unknown Source)
at com.genuitec.pulse.installer.module.ui.progress.GenericProgressPage$GenericProgressJob.run(Unknown Source)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)
Caused by: java.lang.ClassNotFoundException: java.util.jar.Pack200
at java.base/java.lang.ClassLoader.findClass(ClassLoader.java:719)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:588)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:371)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:364)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:161)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
... 14 more
++ END OF ERRORS
具体而言是这句：java.lang.NoClassDefFoundError: java/util/jar/Pack200 。我个人就怀疑是环境的问题，然后重现安装了JAVA的JDK环境。之前安装的版本比较高，现在换成了JDK8，JDK8安装好配置好环境之后，MyEclipse也就成功安装了。
特此记录。