If you forgot the admin password for Sitecore, you can reset it to default (admin/b), by running this SQL script against the core database
[sql]
/*******************************************************************
* PURPOSE: Resets the Sitecore admin password to ‘b’
* DATE AUTHOR
*——————————————————————-
* 04-04-14 Nehemiah J
*******************************************************************/
/* Change the Sitecore DB Name */
USE [SITECORE_CORE_DB]
GO
DELETE FROM [aspnet_Membership] WHERE UserId = N’b09bbcde-9b3c-4dcd-b69e-67f615ce01e9′
GO
DELETE FROM [aspnet_Profile] WHERE UserId = N’b09bbcde-9b3c-4dcd-b69e-67f615ce01e9′
GO
DELETE FROM [aspnet_Users] WHERE UserId = N’b09bbcde-9b3c-4dcd-b69e-67f615ce01e9′
GO
INSERT [dbo].[aspnet_Membership] ([ApplicationId], [UserId], [Password], [PasswordFormat], [PasswordSalt], [MobilePIN], [Email], [LoweredEmail], [PasswordQuestion], [PasswordAnswer], [IsApproved], [IsLockedOut], [CreateDate], [LastLoginDate], [LastPasswordChangedDate], [LastLockoutDate], [FailedPasswordAttemptCount], [FailedPasswordAttemptWindowStart], [FailedPasswordAnswerAttemptCount], [FailedPasswordAnswerAttemptWindowStart], [Comment]) VALUES (N’e0656bf5-52dd-4d6b-a85a-733561eabf65′, N’b09bbcde-9b3c-4dcd-b69e-67f615ce01e9′, N’qOvF8m8F2IcWMvfOBjJYHmfLABc=’, 1, N’OM5gu45RQuJ76itRvkSPFw==’, NULL, N”, N”, NULL, NULL, 1, 0, CAST(0x00009C7E00B986EC AS DateTime), CAST(0x0000A30001519E04 AS DateTime), CAST(0x00009C7E00B986EC AS DateTime), CAST(0xFFFF2FB300000000 AS DateTime), 0, CAST(0xFFFF2FB300000000 AS DateTime), 0, CAST(0xFFFF2FB300000000 AS DateTime), N’Sitecore Administrator’)
GO
INSERT [dbo].[aspnet_Profile] ([UserId], [PropertyNames], [PropertyValuesString], [PropertyValuesBinary], [LastUpdatedDate]) VALUES (N’b09bbcde-9b3c-4dcd-b69e-67f615ce01e9′, N’IsAdministrator:S:0:4:Portrait:S:4:27:FullName:S:31:13:ProfileItemId:S:44:38:SerializedData:B:0:3875:’, N’TruePeople/16×16/Astrologer.pngAdministrator{AE4C4969-5B7E-4B4E-9042-B2D8701CE214}’, 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CAST(0x0000A2F500D2B376 AS DateTime))
GO
INSERT [dbo].[aspnet_Users] ([ApplicationId], [UserId], [UserName], [LoweredUserName], [MobileAlias], [IsAnonymous], [LastActivityDate]) VALUES (N’e0656bf5-52dd-4d6b-a85a-733561eabf65′, N’b09bbcde-9b3c-4dcd-b69e-67f615ce01e9′, N’sitecore\Admin’, N’sitecore\admin’, NULL, 0, CAST(0x0000A3000151A230 AS DateTime))
GO
[/sql]