dual boot - installing 64bit 12.04 LTS along with 32bit window 7

I am facing issues with installing Ubuntu 12.04 LTS (64 bits) alongside Windows 7 (32 bits).

My machine is Intel i5. My current Windows partitions are:

• C: Drive of 50 GB



• D: Drive of 195 GB


• E: Drive of 221 GB


• System Reserved of 100 MB.

I tried to USB boot and install Ubuntu, during the installing process I could see 3 options:

a) install inside Windows 7 b) Erase c) Something else.

I choose "something else" and when proceeded, I could't find all my Windows partitions.

Given below is my fdisk -l report:

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x3e025634


   Device Boot      Start         End      Blocks   Id  System
/dev/sda1              63        2047         992+  42  SFS
/dev/sda2   *        2048      206847      102400   42  SFS
/dev/sda3          206848   102402047    51097600   42  SFS
/dev/sda4       102402048   976771119   437184536   42  SFS

Disk /dev/sdb: 32.0 GB, 32015679488 bytes
255 heads, 63 sectors/track, 3892 cylinders, total 62530624 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x4da96a7f

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *          32    62530623    31265296    c  W95 FAT32 (LBA)

listing below is my parted -l command report.

Model: ATA Hitachi HTS54505 (scsi)

Disk /dev/sda: 500GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 32.3kB 1049kB 1016kB primary ext2
2 1049kB 106MB 105MB primary ntfs boot
3 106MB 52.4GB 52.3GB primary ntfs
4 52.4GB 500GB 448GB primary ntfs

Model: SanDisk Cruzer Force (scsi)
Disk /dev/sdb: 32.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 16.4kB 32.0GB 32.0GB primary fat32 boot, lba

I also tried to execute the command "sudo dmraid -E -r /dev/sda". for which i got error message like "no raid disks and with names: "/dev/sda".

How should I proceed?