Windows, Vista: How to Extend System Partition

Warning: First Backup Your Data. Altering the partitions can be risky. You must know what you are doing.

To extend system partition you can use Windows Disk Managment or second part application.

Windows Disk Managment
Windows 7 Disk Management can expand the system partition, but there must be some unallocated space next to the partition. Unallocated disk space means a raw partition which is not formatted with a valid file system (e.g. FAT. NTFS).

You have only partition C and unallocated space:
1) Before You will extend partition C You must defragment it.
2) Go to Control Panel -> Administrative Tools -> Disk Management
3) Extend partition.

You have partition D and you don’t have unallocated space next to partition C:
1) Copy All Your Data from partition D to USB hard disk
2) Go to Control Panel -> Administrative Tools -> Disk Management
3) Right-click partition D
4) Click Delete Volume.
5) Shrink partiton C.
6) Create partition D
7) Copy All Your Data from USB hard disk to partiton D.
or
Warning: Four is the maksimum of primary partitions.
1) Shrink partition D
2) Create new partition E
3) Move All Your Data from partition D to partition E
4) Delete Volume D
5) Shrink partition C

The problem is that if you resize your boot/system partition, you will be completely unable to boot without repairing windows. First make sure that you have a bootable Windows Vista installation DVD.

Gparted Boot Disk (free software GNU GPLv2):
How to use Gparted

AOMEI Partition Assistant Standard Edition (allows commercial use)

Paragon Partition Manager (only Free for personal use)

Troubleshooting:
1) Very slow running Windows because it was only a few MB on the hard disk where is one partition and unallocate space.

Solution:
1) Run Gparted
2) Resize partition C
3) Run Vista installation DVD (if something went wrong)
4) Rapair system.

2) Very slow running Windows. There is only a few MB on partition C. Next to is partition D.

Solution:
1) Run Gparted
2) Copy data from D to external USB Hard Disk.
3) Delete partiton D
4) Resize partition C
5) Create partition D
6) Copy data from USB Hard Disk to partition D.
7) Run Vista installation DVD (if something went wrong)
8) Rapair system.