Hello Leandre, welcome to Seven Forums!
It is always better to do a wipe of the entire Hard Disk Drive first, have a look through the information below and be sure to post back with any further questions you may have and to keep us informed.
No matter what you do, if you do a
clean install you will have to reinstall all the programs/apps that you use as they integrate themselves into the Windows registry and are not moveable from one Windows installation to another so be sure to save the program activation keys where applicable.
After you have
copied out or made
back-ups of the data you need to save to external media, use Step One of this tutorial at the first link below to do a wipe (
secure erase) to the entire Hard Disk Drive / Solid State Drive.
- Then if you do not want to create the new Windows 7 "System Reserved" partition use the outline in Step Two #2 to create, format and mark Active a single 100GB partition to do the installation to.
- If you do want to create the "System Reserved" partition use the outline in Step Two #3 to create, format and mark Active the System Reserved partition and then create and format the 100GB partition to do the installation to.
Either way, running the "clean all" then creating and formatting the partition(s) using diskpart will get you the best possible space to do a
clean install of Windows 7 to; you can always
extend the Windows partition to include the remaining unallocated space on the HDD / SSD or
create additional Primary partitions or an
Extended partition after the installation completes if you choose.
SSD / HDD : Optimize for Windows Reinstallation
DISKPART : At PC Startup
Do a Clean Install with a Upgrade Windows 7 Version
