I can't install or remove windows 7 or later using Boot Camp Assistant?

I tried for a couple days to install Windows 7 on my MacBook Pro which has OSX Yosemite (10.10.2). As you see in the capture, the third checkbox is disabled. I have created a Windows 7 Install disk on a USB flash and downloaded the latest Windows support software from Apple, all I have to do is install it on the Mac.

What's the problem here?

---

EDIT:

ADDED THIS INFORMTION FOR DAVID ANDERSON'S ANSWER.

1. 
   

   I checked the latest firmware, every thing was OK except Boot ROM Version, mine was( MBP101.00EE.B07), I tried to update it but the last number was different MBP101.00EE.B02

   
   


2. 
   

   Model Identifier: MacBookPro10,1

   
   


3. Last night I Removed every thing on my Mac and then I used the Internet recovery for installing the OS again, It was successful.


4. My internet is not very bad, 600KB/s, and the boot was fast.


5. I did backups using TimeMachine, and also created image using Disk Utility.


6. I have a USB connected, I can write/read because it's formatted MS-DOS(FAT).


7. Before I buy this Mac, I had a PC running Windows 7. I have 8 years experience in Windows, but I'm totally new to Mac OS.

And for the Out put of the commands, here it is:

Last login: Fri Feb 13 13:36:10 on ttys000
Azads-MBP:~ Azad$ diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *751.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS WINDOWS                 100.0 GB   disk0s2
   3:                  Apple_HFS MAC DATA 1              325.5 GB   disk0s3
   4:          Apple_CoreStorage                         324.7 GB   disk0s4
   5:                 Apple_Boot Recovery HD             650.0 MB   disk0s5
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS MAC OS                 *324.3 GB   disk1
                                 Logical Volume on disk0s4
                                 XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
                                 Unencrypted
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *31.2 GB    disk2
   1:                 DOS_FAT_32 WININSTALL              31.2 GB    disk2s1
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     Apple_partition_scheme                        *126.7 MB   disk3
   1:        Apple_partition_map                         30.7 KB    disk3s1
   2:         Apple_Driver_ATAPI                         2.0 KB     disk3s2
   3:                  Apple_HFS MacBook Pro Retina E... 126.7 MB   disk3s3


Azads-MBP:~ Azad$ diskutil cs list
CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
    =========================================================
    Name:         MAC OS
    Status:       Online
    Size:         324682784768 B (324.7 GB)
    Free Space:   18882560 B (18.9 MB)
    |
    +-< Physical Volume XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
    |   ----------------------------------------------------
    |   Index:    0
    |   Disk:     disk0s4
    |   Status:   Online
    |   Size:     324682784768 B (324.7 GB)
    |
    +-> Logical Volume Family XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
        ----------------------------------------------------------
        Encryption Status:       Unlocked
        Encryption Type:         None
        Conversion Status:       NoConversion
        Conversion Direction:    -none-
        Has Encrypted Extents:   No
        Fully Secure:            No
        Passphrase Required:     No
        |
        +-> Logical Volume XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
            ---------------------------------------------------
            Disk:                  disk1
            Status:                Online
            Size (Total):          324311580672 B (324.3 GB)
            Conversion Progress:   -none-
            Revertible:            Yes (no decryption required)
            LV Name:               MAC OS
            Volume Name:           MAC OS
            Content Hint:          Apple_HFS



Azads-MBP:~ Azad$ sudo gpt -r -vvv show -l /dev/disk0
Password:
gpt show: /dev/disk0: mediasize=751277983744; sectorsize=512; blocks=1467339812
gpt show: /dev/disk0: PMBR at sector 0
gpt show: /dev/disk0: Pri GPT at sector 1
gpt show: /dev/disk0: GPT partition: type=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX, start=40, size=409600
gpt show: /dev/disk0: GPT partition: type=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX, start=409640, size=195312496
gpt show: /dev/disk0: GPT partition: type=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX, start=195984280, size=635677744
gpt show: /dev/disk0: GPT partition: type=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX, start=831924168, size=634146064
gpt show: /dev/disk0: GPT partition: type=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX, start=1466070232, size=1269544
gpt show: /dev/disk0: Sec GPT at sector 1467339811
       start        size  index  contents
           0           1         PMBR
           1           1         Pri GPT header
           2          32         Pri GPT table
          34           6         
          40      409600      1  GPT part - "EFI System Partition"
      409640   195312496      2  GPT part - "WINDOWS"
   195722136      262144         
   195984280   635677744      3  GPT part - "MAC DATA 1"
   831662024      262144         
   831924168   634146064      4  GPT part - "MAC OS"
  1466070232     1269544      5  GPT part - "Recovery HD"
  1467339776           3         
  1467339779          32         Sec GPT table
  1467339811           1         Sec GPT header



Azads-MBP:~ Azad$ sudo fdisk /dev/disk0
Disk: /dev/disk0    geometry: 91337/255/63 [1467339812 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE 1023 254  63 - 1023 254  63 [         1 - 1467339811] <Unknown ID>
 2: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
 3: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused      
Azads-MBP:~ Azad$