When I connect through Workgroup it shows Guest Account Disabled.......

On any XP Pro computer, check to see if Simple File Sharing (Control Panel -
Folder Options - View - Advanced settings) is enabled or disabled. With XP Pro,
you need to have the SFS settings properly set on each computer.

With XP Pro, if SFS is disabled, check the Local Security Policy (Control Panel
- Administrative Tools). Under Local Policies - Security Options, look at
"Network access: Sharing and security model", and ensure it's set to "Classic -
local users authenticate as themselves".

With XP Pro, if you set the Local Security Policy to "Guest only", make sure
that the Guest account is enabled, thru Local User Manager (Start - Run -
"lusrmgr.msc"), and has an identical, non-blank, password on all computers. If
"Classic", setup and use a common non-Guest account, with identical, non-blank,
password on all computers.

For XP Home, OR for XP Pro with Simple File Sharing enabled, make sure that the
Guest account is enabled, thru Local User Manager (Start - Run - "lusrmgr.msc"),
on each computer.