Fails to install on Umbraco 7 and now my whole site is inaccessible including admin section

[samthomson]

Stack Trace:

[DuplicateNameException: An item with the alias CWSMember already exists] Umbraco.Core.Persistence.Repositories.ContentTypeBaseRepository2.PersistNewBaseContentType(ContentTypeDto dto, IContentTypeComposition entity) +2742 Umbraco.Core.Persistence.Repositories.MemberTypeRepository.PersistNewItem(IMemberType entity) +337 Umbraco.Core.Persistence.Repositories.RepositoryBase2.PersistNewItem(IEntity entity) +156 Umbraco.Core.Persistence.UnitOfWork.PetaPocoUnitOfWork.Commit(Action1 transactionCompleting) +217 Umbraco.Core.Persistence.UnitOfWork.PetaPocoUnitOfWork.Commit() +7 Umbraco.Core.Services.MemberTypeService.Save(IMemberType memberType, Int32 userId) +182 umbraco.cms.businesslogic.member.MemberType.MakeNew(User u, String Text) +174 CWSStart.Web.CWSExtensions.RegisterStartupEvents.AddCustomMemberType() in c:\inetpub\wwwroot\Personal\CWS-Start\CWSStart.Web\CWSStart.Web\CWSExtensions\RegisterStartupEvents.cs:92 CWSStart.Web.CWSExtensions.RegisterStartupEvents.ApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext) in c:\inetpub\wwwroot\Personal\CWS-Start\CWSStart.Web\CWSStart.Web\CWSExtensions\RegisterStartupEvents.cs:48 Umbraco.Core.ApplicationEventHandler.OnApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext) +37 Umbraco.Core.CoreBootManager.<Complete>b__5(IApplicationEventHandler x) +36 Umbraco.Core.EnumerableExtensions.ForEach(IEnumerable1 items, Action1 action) +141 Umbraco.Core.CoreBootManager.Complete(Action1 afterComplete) +93 Umbraco.Web.WebBootManager.Complete(Action`1 afterComplete) +39 Umbraco.Core.UmbracoApplicationBase.StartApplication(Object sender, EventArgs e) +166 Umbraco.Core.UmbracoApplicationBase.Application_Start(Object sender, EventArgs e) +9

[HttpException (0x80004005): An item with the alias CWSMember already exists] System.Web.HttpApplicationFactory.EnsureAppStartCalledForIntegratedMode(HttpContext context, HttpApplication app) +398 System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +850 System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +675 System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +183 System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +280 System.Web.HttpApplicationFactory.GetPipelineApplicationInstance(IntPtr appContext, HttpContext context) +56 System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +174

[HttpException (0x80004005): An item with the alias CWSMember already exists] System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +527 System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +84 System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +166