I think you have a logical partition inside an extended partition.
That is indicated by 'sda5` (a number greater than 4; max primary partitions).
- What is the difference between “extended” partition and “logical” partition
- Partition / Extended: Logical Drives at SevenForums
- Disk Partitioning at Wikipedia
Update on your comment,
Making your Win7 in logical partition move to a primary is not that straight forward :-)
However, if you are fine to delete all logical partitions (seen inside the flipped triangle, as you call it), you can then remove the extended partition itself (note that you will loose your Win7 and any other logical partitions along with their data when you do this). After you do this, you can create a new primary partition of the same size 'sda5' shows now and then install Win7 freshly into that.
This would give you a Win7 primary partition (probably seen as 'sda2' in GParted).
Some other basic facts: You can have at most 4 primary partitions. That is why, your extended partition shows logical partitions starting from 'sda5'. Given your description, I see that you have one primary partition (sda1) with Vista and wish to have another primary partition (sda2) with Win7. If you have further disk-space after these two partitions, you can make another couple (at most) primary partitions or just make an extended partition for many more logical partitions for your data.