What is a remaster at boot followed by Startup Repair? Sounds interesting.
If you have data that needs to be overwritten out of reach of data recovery software, then i would run Diskpart Clean All Command
from the booted Windows 7 installer or System Repair Disk
. However this completely wipes the HD with zeroes.
Then you'll need to either run your Recovery Disks which came with the computer, were made when you set it up or can still be made now, or do a Clean Reinstall - Factory OEM Windows 7
If you want to just clean up the Windows 7 you have on there now, delete all files in each of the named User folders, the Public folders, C drive root, any data partitions.
Then run CCleaner Disk and Registry tabs Cleaners, on its Tools tab choose Drive Wiper and wipe the Drive's free space with 3 passes which should make all of your deleted data irretrievable by any software.
Finish the cleanup by running Puran free boot time defrag with Disk check to perfectly order the HD and check it's condtion at the same time. Puran Defrag Free Edition - Free software downloads and software reviews - CNET Download.com