I would update all programs
make lots of notes about hardware
find and download drivers for w7
find and save drivers for w8 to external source
Use the sonar plugin manager to export all presets saved using the sonar preset format.
Image the disk.
Get a new disk, install, install window 8.1.1, and all updates.
Install the hardware drivers previously downloaded.
Once done, image again.
Windows 8.1.1 can be configured to mostly never show the start walls of unhappiness.
Starting anew: I recommend windows 8+ for next 3+ years
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Last time I did this took more than a month to get all software installed and usable. Limited time, dual boot, clean install on new disk" :: for me: install adobe, java,... configure windows to use desktop programs, install office and all updates and configure (I use spreadsheets for most all lyrics and tracking of projects and notes), install a many sonar versions and updates, and import sonar presets, install 3rd party programs, instruments and tools and conversion utilities, and so on.
Image again.
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When ready, use the manufacture's disk utility to write zeros to the original disk. I have "saved," and "rehabilitated," disks indicating failure by doing this.