Because partition manager in NT/2000/2003/XP will not let you resize a basic drive partition without losing data and you can't convert a basic system disc to Dynamic in some circumstances if the O/S was installed on a basic disc.
When Windows server came out, 10GB partition was big enough, but with all the Spacks / updates, a minimum of 20GB is what's needed now. These programmes, Easeus in particular has allowed me to resize my system partitions without a problem to stop the servers complaining of no space on the system drive. I use a licensed copy of Easeus, Active@Boot (which is a boot disc system that incorporates the Activ@partition and have also used Paragon & GParted.
These four have enabled me to recover from some very sticky situations over the years including broken Raid 5 systems! I also use a very low level programme from Boot-IT. Ever wanted to change an NTFS system to FAT32 just by changing the Bit, and editing MBR Don't do it on live systems though
Never used the other programmes though.
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