Error with server start (5 replies)

I installed the Mysql workbench and the Mysql community server on my pc ( win xp 32 bit ) , the first time I installed the server it worked fine , the line came up and said if you need help type /help or whatever , but now no matter what I do I can't get the server to start , I reinstalled it like 3 times did registry cleaner , system cleaner and restarted my pc with no luck still ,heres my code :

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Program Files\MySQL\MySQL Server 5.1\bin>mysqld.exe --console
100724 12:10:13 [Warning] '--default-character-set' is deprecated and will be re
moved in a future release. Please use '--character-set-server' instead.
100724 12:10:13 [Note] Plugin 'FEDERATED' is disabled.
mysqld.exe: File '.\mysql\plugin.MYD' not found (Errcode: 2)
mysqld.exe: Can't find file: 'plugin' (errno: 2)
100724 12:10:14 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgr
ade to create it.
InnoDB: Log scan progressed past the checkpoint lsn 0 37356
100724 12:10:14 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
InnoDB: Doing recovery: scanned up to log sequence number 0 44233
100724 12:10:14 InnoDB: Starting an apply batch of log records to the database.
..
InnoDB: Progress in percents: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 7
3 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

InnoDB: Apply batch completed
100724 12:10:15 InnoDB: Started; log sequence number 0 44233
100724 12:10:15 [ERROR] Fatal error: Can't open and lock privilege tables: File
'.\mysql\host.MYD' not found (Errcode: 2)

C:\Program Files\MySQL\MySQL Server 5.1\bin>