DebuggingWordCountTest Fails on Windows

It fails with below error on windows Vista:

org.apache.beam.sdk.Pipeline$PipelineExecutionException: java.lang.IllegalStateException: Unable to find registrar for c
at org.apache.beam.sdk.Pipeline.run(Pipeline.java:303)
at org.apache.beam.sdk.Pipeline.run(Pipeline.java:283)
at org.apache.beam.examples.DebuggingWordCount.main(DebuggingWordCount.java:160)
at org.apache.beam.examples.DebuggingWordCountTest.testDebuggingWordCount(DebuggingWordCountTest.java:50)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
at org.junit.rules.RunRules.evaluate(RunRules.java:20)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: java.lang.IllegalStateException: Unable to find registrar for c
at org.apache.beam.sdk.io.FileSystems.getFileSystemInternal(FileSystems.java:447)
at org.apache.beam.sdk.io.FileSystems.match(FileSystems.java:111)
at org.apache.beam.sdk.io.FileBasedSource.getEstimatedSizeBytes(FileBasedSource.java:207)
at org.apache.beam.runners.direct.BoundedReadEvaluatorFactory$InputProvider.getInitialInputs(BoundedReadEvaluatorFactory.java:207)
at org.apache.beam.runners.direct.ReadEvaluatorFactory$InputProvider.getInitialInputs(ReadEvaluatorFactory.java:87)
at org.apache.beam.runners.direct.RootProviderRegistry.getInitialInputs(RootProviderRegistry.java:62)

Imported from Jira [BEAM-2578](https://issues.apache.org/jira/browse/BEAM-2578). Original Jira may contain additional context.
Reported by: apacheenthu.

Start with examples DebuggingWordCountTest.testDebuggingWordCount and DebuggingWordCount.main, then trace the failure into FileSystems.getFileSystemInternal and FileSystems.match. Reproduce the test on Windows and identify why the registrar for the c path is unavailable; done means the test passes there without the reported PipelineExecutionException.

Written by the indexing model from the issue text.