Multi-boot systems with Linux and Windows are quite common. With the following steps, it is easy to access Windows partitions under Linux.

1. Examine the disk partitions. For example,

sudo fdisk -l

gives the output,

Disk /dev/sda: 160.0 GB, 160041885696 bytes  
255 heads, 63 sectors/track, 19457 cylinders  
Units = cylinders of 16065 * 512 = 8225280 bytes  
Disk identifier: 0x093fba08  

Device Boot      Start         End      Blocks   Id  System  
/dev/sda1   *           1        9311    74790576    7  HPFS/NTFS  
/dev/sda2           18456       19457     8048565    7  HPFS/NTFS  
/dev/sda3            9312       11622    18563107+  bf  Solaris  
/dev/sda4           11623       18455    54886072+   5  Extended  
/dev/sda5           11623       11747     1004031   82  Linux swap / Solaris  
/dev/sda6           11748       12356     4891761   83  Linux  
/dev/sda7           12357       16004    29302528+  83  Linux  
/dev/sda8           16005       18455    19687626   83  Linux

/dev/sda1 and /dev/sda2, here, refer to the Windows’ C and D drives respectively.

2. Create directories for local mount under /media

sudo mkdir /media/C 
sudo mkdir /media/D

3. Update the /etc/fstab file

Add the following line to /etc/fstab

<disk_partition>  <local_mount_point> ntfs rw,nls=utf8,umask=022 0 0

In the above example, the following two lines are added to /etc/fstab,

/dev/sda1  /media/C  ntfs  rw,nls=utf8,umask=022 0 0 
/dev/sda2  /media/D  ntfs  rw,nls=utf8,umask=022 0 0

4. Reboot the system.

Now the C and D drives should be accessible as /media/C and /media/D respectively.