i have 640GB hard drive acer aspire 5750 intel core I5 which i have 3 partitions on it.,, i wanted to dual boot with ubuntu linux 12.04 lts but every shrunk space allocated i made is unusable on each partition. On DRIVE C: I have 97.56GB , D: 200.43GB , E: 298.08. what i did was after shrinking the drive i restart & recheck if i can install it there., but the device is still unusable status. please tell me
what is the best way or where to install it? or should i delete the contents or drive D: shrink it along with drive C: & repartition.

If you shrink a partition, you create unallocated space which is not on a partition and you will then need to create a new partition on which to perform the installation.

To post some information that could help, boot the Ubuntu CD and enter a terminal which you can do by holding down the Ctrl+Alt+t keys simultaneously. Then enter this command: sudo fdisk -l(Lower case Letter L in the command). Post the output here as that will show partition information.

Also, naming conventions for Linux are not the same as windows and you will not see 'C' or 'D' in reference to drives/partitions. If you currently have three partitions, you should be able to create another to install Linux. At what point in the installation do you have problems. More specifics on the steps would be useful for someone to help you.

particularly on windows disk management i made 150GB unallocated space which i intend to install linux , but during the installation type the device named into unusable although it diplayed free space of 150GB & from that space i wanted to add a logical & primary partion manually but i cant create..i get stuck.https://help.ubuntu.com/community/GraphicalInstall

Please boot into the Ubuntu live-system and use the terminal to launch the command (lowercase L, not the number one).
Post the output here.

Is the Installation Type screen in the link you posted where it stops? Did you select the "Something Else" option? That would be best as you will have more control and be able to see the steps as they occur during the install.

I have no idea what you mean by that statement?

The link you posted above is an oversimplified explanation. If you use the "Something Else" option you will get another screen, Allocate Drive Space, which will show the drives and partitions on your computer and if you have free space, you need to click on it in the main window to highlight it then click the Add tab below the main window to Create and format a partition. If you already have a partition, you will need to format it and select a mount point for the system which should be "/", without the quotes.

You need to post more specific information on where you are running into problems.

yes i use " something else" option and on the next screen i saw all the drives & i highlighted the freespace but the add tab is not working. the format should be like this.

Device type mountpoint format size used
/dev/sda
/dev/sda1 ntfs 104mn 104MB
/dev/sda2 ntfs 104752MB 104752MB
/dev/sda3 ntfs 131324MB 131324MB
freespace 83886MB


but the result is, on the last device freespace is like this, see below. and the add tab for that is not working.

unusable 83886MB

After highlighting free space in the main window, you should then be able to click the Add tab and get a new "Create a New Partition" window so if that isn't happening, you might have had a bad download or a bad burn of the iso to CD/DVD. Do you have another computer available on which you can try to boot the CD to see if it works?

It would also be useful if you could boot the Ubuntu CD and run the "fdisk" command suggested by TobiSGD above. Post the output here. If you have only three partitions you should be able to install. Also, post the entire output of the command not just the partitions.

I think this is your problem.
You already have 3 Windows partitions, which you have identified as C, D, and E. I would assume that these are all primary partitions.
You are trying to create one additional logical partition plus another primary partition. You can only have 4 primary partitions. If you have 4 primary partitions you can not add an additional logical partition.
If you have three primary plus one logical partition, you can not add an additional primary partition.

Choose "something else" during the partitioning part of the Ubuntu install.
In the unallocated space that you have created, create two logical partitions. One will be for the root partition and one will be for the swap partition.
If you have a good amount of memory, you can set the swap partition to 1 GB. The rest can be the root partition.

You could also go with three logical partitions. One would be for root (about 20GB).
One would be for swap (1 GB).
The rest would be for the home partition, which is where all of your data and user settings are stored.

to yancek : i successfully installed it on another laptop which it has 2 partitions & installed linux on 3rd partition.

to tommcd : yes that is my problem i cant add for one logical & primary partition, but i'll try it again..

to tobi : ,i didnt try it yet but i will..

thanks for all the infos & suggestions uhm i'll give you post when im done..

its my 3rd day now on linux...again thanks for the help..