How can I delete files without growing MFT zone size ?

[lordsepid]

Hi

I'm trying to install my windows xp unattendedly through winnt32.exe

the only problem is when i install the new windows and delete the old one at RunOnceEx, it doesn't show the right size of the windows drive. after a few search i found out that this is because of the MFT zone size which grows and doesn't let the free space become unallocated. and this causes the used space become double than the real size. (at least 2.5 GB is lost)

I know i can format the drive but i've made this phase of setup unattended.

my question is, is it possible to remove the temp files without losing the free space to MFT zone ?