I tried to convert logical drive into primary partition using Easeus Partition Master,but it shows an error telling that "There is no empty slot in MBR Partition Table".
There are 5 partitions present in my computer;i.e,
C,D,E,F,G in which win xp is installed in D and win 7 in C and other data in E,F,G.
I want to convert drive C(Win 7) from logical to primary.
How can I do so?

Drives using a master boot record (MBR) (http://en.wikipedia.org/wiki/Master_boot_record) partitioning scheme can have four primary partitions or 3 primary partitions and an extended partition. The extended partition can be subdivided into numerous logical partitions, each usually being assigned a logical drive letter. If C is a portion of an extended partition, one or more logical drives and/or partitions will need to be backed-up, deleted, the drive repartitioned as desired, and then the backed-up data restored to the desired partitions. I'm not familiar with Easeus, it may have features to achieve and automate this process. Boot configuration entries for both operating systems may need manual adjustment once repartitioning is done for the machine to boot to the proper partition, now changed. The boot sector may also need to be rebuilt if the system volume changed.

Hi Scleros
Thanks for your reply.But I completed the work using other method.Actually I wanted to remove Xp from dual boot with 7.Win 7 was installed in a logical drive and therefore could not be marked as active.[According to my knowledge].So,if I had deleted the xp partition,then the computer would not boot because win 7 was in logical drive and could not made as active one.
I am not sure what I did is correct.
First,I booted the computer from Win 7 cd and selected to repair the computer.Then under that,I selected the command prompt option through which the xp partition was deleted and other primary partiton which did not contain any OS was made active.Later I typed the command "Bootrec /fixboot" "bootrec /rebuildbcd" and "bootrec /fixmbr" which solved all my problems.Then the computer was restarted and it booted directly to Win 7 with ease.
I hope you understood what I wrote and will give suggestions accordingly.

I am not sure what i did is correct.

There isn't a "right" or "wrong" way if the outcome you desired was achieved, however there may be optimal and non-optimal ways. What did you do with the unused free space on the drive generated by the deleted partition?

Yup,got some free space for my music and especially for "Softwares".