C# - Thread Is Being Aborted While Deleting Folders?

I am using web service method to run scripts it generated the some unwanted folders i want to delete folders after or before the script runs.

ProcessStatus newProcess =
new ProcessStatus(
String.Format(
"{0}, started:{1}",
projectName, DateTime.Now.ToString("HH:m:ss")
)
);
newProcess.buildData = new BuildHelper(deviceName, projectName, owner, deviceFolder, Constants.serverContentpath, Constants.buildInfoFilePath);
ProcessStatuses processStatus = new ProcessStatuses();
ArrayList allProcesses = processStatus.Get();
ArrayList.Synchronized(allProcesses).Add(newProcess);
ThreadPool.QueueUserWorkItem(
new WaitCallback(processStatus.startProcessing),
new object[] { newProcess, allProcesses }
);
//Thread th = new Thread(new ThreadStart(delegate {
// processStatus.startProcessing(new object[] { newProcess, allProcesses });
//}));
//th.Start();
processStatus = null;
newProcess = null;
_deviceBuildMonitor = null;