Instalando o GitHub para Windows

Estou tentando instalar o GitHub para Windows. Eu tentei instalá-lo da maneira normal e recebi este erro:

Application installation did not succeed. Cannot locate application files on the server. Contact the application vendor or your administrator for assistance.

Clicando emDetails... me deu isso:

PLATFORM VERSION INFO
    Windows             : 6.1.7601.65536 (Win32NT)
    Common Language Runtime     : 4.0.30319.18034
    System.Deployment.dll       : 4.0.30319.17929 built by: FX45RTMREL
    clr.dll             : 4.0.30319.18034 built by: FX45RTMGDR
    dfdll.dll           : 4.0.30319.17929 built by: FX45RTMREL
    dfshim.dll          : 4.0.41209.0 (Main.041209-0000)

SOURCES
    Deployment url          : http://github-windows.s3.amazonaws.com/GitHub.application
                        Server      : AmazonS3
    Application url         : http://github-windows.s3.amazonaws.com/Application%20Files/GitHub_1_0_47_0/GitHub.exe.manifest
                        Server      : AmazonS3

IDENTITIES
    Deployment Identity     : GitHub.application, Version=1.0.47.0, Culture=neutral, PublicKeyToken=317444273a93ac29, processorArchitecture=x86
    Application Identity        : GitHub.exe, Version=1.0.47.0, Culture=neutral, PublicKeyToken=317444273a93ac29, processorArchitecture=x86, type=win32

APPLICATION SUMMARY
    * Installable application.
    * Trust url parameter is set.
ERROR SUMMARY
    Below is a summary of the errors, details of these errors are listed later in the log.
    * Activation of http://github-windows.s3.amazonaws.com/GitHub.application resulted in exception. Following failure messages were detected:
        + Downloading http://github-windows.s3.amazonaws.com/Application Files/GitHub_1_0_47_0/msvcp100.dll.deploy did not succeed.
        + The remote server returned an error: (403) Forbidden.

COMPONENT STORE TRANSACTION FAILURE SUMMARY
    No transaction error was detected.

WARNINGS
    There were no warnings during this operation.

OPERATION PROGRESS STATUS
    * [5/21/2013 8:19:19 AM] : Activation of http://github-windows.s3.amazonaws.com/GitHub.application has started.
    * [5/21/2013 8:19:19 AM] : Processing of deployment manifest has successfully completed.
    * [5/21/2013 8:19:19 AM] : Installation of the application has started.
    * [5/21/2013 8:19:20 AM] : Processing of application manifest has successfully completed.
    * [5/21/2013 8:19:24 AM] : Found compatible runtime version 4.0.30319.
    * [5/21/2013 8:19:24 AM] : Request of trust and detection of platform is complete.

ERROR DETAILS
    Following errors were detected during this operation.
    * [5/21/2013 8:19:25 AM] System.Deployment.Application.DeploymentDownloadException (Unknown subtype)
        - Downloading http://github-windows.s3.amazonaws.com/Application Files/GitHub_1_0_47_0/msvcp100.dll.deploy did not succeed.
        - Source: System.Deployment
        - Stack trace:
            at System.Deployment.Application.SystemNetDownloader.DownloadSingleFile(DownloadQueueItem next)
            at System.Deployment.Application.SystemNetDownloader.DownloadAllFiles()
            at System.Deployment.Application.FileDownloader.Download(SubscriptionState subState)
            at System.Deployment.Application.DownloadManager.DownloadDependencies(SubscriptionState subState, AssemblyManifest deployManifest, AssemblyManifest appManifest, Uri sourceUriBase, String targetDirectory, String group, IDownloadNotification notification, DownloadOptions options)
            at System.Deployment.Application.ApplicationActivator.DownloadApplication(SubscriptionState subState, ActivationDescription actDesc, Int64 transactionId, TempDirectory& downloadTemp)
            at System.Deployment.Application.ApplicationActivator.InstallApplication(SubscriptionState& subState, ActivationDescription actDesc)
            at System.Deployment.Application.ApplicationActivator.PerformDeploymentActivation(Uri activationUri, Boolean isShortcut, String textualSubId, String deploymentProviderUrlFromExtension, BrowserSettings browserSettings, String& errorPageUrl)
            at System.Deployment.Application.ApplicationActivator.ActivateDeploymentWorker(Object state)
        --- Inner Exception ---
        System.Net.WebException
        - The remote server returned an error: (403) Forbidden.
        - Source: System
        - Stack trace:
            at System.Net.HttpWebRequest.GetResponse()
            at System.Deployment.Application.SystemNetDownloader.DownloadSingleFile(DownloadQueueItem next)

COMPONENT STORE TRANSACTION DETAILS
    No transaction information is available.

Eu segui o conselho sobreesta postagem e baixadogithub-windows.s3.amazonaws.com/GitHub.application com a versão mais recente do Chrome. Quando tentei executá-lo, recebi este erro:

Application cannot be started. Contact the application vendor.

Com esse detalhe:

PLATFORM VERSION INFO
    Windows             : 6.1.7601.65536 (Win32NT)
    Common Language Runtime     : 4.0.30319.18034
    System.Deployment.dll       : 4.0.30319.17929 built by: FX45RTMREL
    clr.dll             : 4.0.30319.18034 built by: FX45RTMGDR
    dfdll.dll           : 4.0.30319.17929 built by: FX45RTMREL
    dfshim.dll          : 4.0.41209.0 (Main.041209-0000)

SOURCES
    Deployment url          : file:///C:/Users/SESA277661/Downloads/GitHub.application

IDENTITIES
    Deployment Identity     : GitHub.application, Version=1.0.47.0, Culture=neutral, PublicKeyToken=317444273a93ac29, processorArchitecture=x86

APPLICATION SUMMARY
    * Installable application.
    * Trust url parameter is set.
ERROR SUMMARY
    Below is a summary of the errors, details of these errors are listed later in the log.
    * Activation of C:\Users\SESA277661\Downloads\GitHub.application resulted in exception. Following failure messages were detected:
        + Deployment and application do not have matching security zones.

COMPONENT STORE TRANSACTION FAILURE SUMMARY
    No transaction error was detected.

WARNINGS
    There were no warnings during this operation.

OPERATION PROGRESS STATUS
    * [5/21/2013 8:29:33 AM] : Activation of C:\Users\SESA277661\Downloads\GitHub.application has started.
    * [5/21/2013 8:29:33 AM] : Processing of deployment manifest has successfully completed.
    * [5/21/2013 8:29:33 AM] : Installation of the application has started.

ERROR DETAILS
    Following errors were detected during this operation.
    * [5/21/2013 8:29:33 AM] System.Deployment.Application.InvalidDeploymentException (Zone)
        - Deployment and application do not have matching security zones.
        - Source: System.Deployment
        - Stack trace:
            at System.Deployment.Application.DownloadManager.DownloadApplicationManifest(AssemblyManifest deploymentManifest, String targetDir, Uri deploymentUri, IDownloadNotification notification, DownloadOptions options, Uri& appSourceUri, String& appManifestPath)
            at System.Deployment.Application.DownloadManager.DownloadApplicationManifest(AssemblyManifest deploymentManifest, String targetDir, Uri deploymentUri, Uri& appSourceUri, String& appManifestPath)
            at System.Deployment.Application.ApplicationActivator.DownloadApplication(SubscriptionState subState, ActivationDescription actDesc, Int64 transactionId, TempDirectory& downloadTemp)
            at System.Deployment.Application.ApplicationActivator.InstallApplication(SubscriptionState& subState, ActivationDescription actDesc)
            at System.Deployment.Application.ApplicationActivator.PerformDeploymentActivation(Uri activationUri, Boolean isShortcut, String textualSubId, String deploymentProviderUrlFromExtension, BrowserSettings browserSettings, String& errorPageUrl)
            at System.Deployment.Application.ApplicationActivator.ActivateDeploymentWorker(Object state)

COMPONENT STORE TRANSACTION DETAILS
    No transaction information is available.

A partir daqui estou preso. Qualquer conselho seria muito apreciado.

Eu estou em um computador de trabalho, então pode haver algumas configurações de segurança bloqueando alguma coisa, mas eu não sei sobre tudo isso.

Obrigado, chris