Difference in Drive size in Parent and linked clone

Hi Team,

I am doing Vsphere 5.2 Horizon view Implementation . Implementation is going smooth but i have observed one c drive free space difference in Parent and Linked clone .

Windows 7 with Service pack 1 built with Optimization script to disable unwanted services. Free space in parent image c drive is 3.90 GB. when i Provisioned linked clone from that parent image snapshot i found free space in linked clone vdi is approx 6.5 GB.

Please clarify if anyone face the same or it is normal in linked clone.

Thanks

Ravindra.