I have a problem with my HD, it has specific allowed capacity, I can not expand its partition space. Any advice with this?

you have to be more detailed and specific about what you're trying to do, how you went about doing it, and what results did you get.

Please mention the type of partition which you have done on the harddisk and what tool you used to partition. If the harddisk was used to install windows operating system, please mention the type of formating done and other details. Any way i would suggest you to use a disk manager of the specific disk manufacturer which will have options. All this depends on the status of your harddisk and if you are Server running on it.

1) Revise that the external hard drive is empty becuase once you will begin the partition process all data on that drive will be erased completely.
2) From the Micrsosoft console type MMC, this from the Windows start menu.
3) Add the Disk Manager snap-in. This can be also done from File menu and select add napp-in. Click Disk manager from the list.
4) Right-click on the disk in the list of disk at the bottom of the snap-in. You will see a short-cut menu which will give you different options in reference to the partition drive. Here you have the option of either:Expand the partition, delete the partition or shrink the partition. Also you get the possibility of check this as a primary partition if you wish to.
5) Here you can format the new partitions where you utilize the same short-cut menu. In here you must format all partitions you intend to use. It is also an option to set this using the drive letters, this way your operating system will recognize which drive is which letter.

I don't think anyone here is understanding you.. you need to explain this more.

Thread closed due to its age. Please check the date of the OP before posting guys, I doubt the OP will make a comeback at this one.