I agree, that's a great site for how to install it and what it does.
It's basically two things...the ability to have an app run inside a sandbox and also for application compatibility - mainly for those companies with in-house built applications that won't work with anything but Windows XP.
Ollie, you can read more about the detailed requirements and information about this at the link I posted above. However, yes it will have access to your drives if your computer supports virtualization. It will also place shortcuts of the installed programs in XP Mode also into the Windows 7 Start Menu to run only them quickly in XP mode.
My Computer
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Self built custom
OS
64-bit Windows 11 Pro for Workstations
CPU
Intel i7-8700K OC'd to 5 GHz
Motherboard
ASUS ROG Maximus XI Formula Z390
Memory
64 GB (4x16GB) G.SKILL TridentZ RGB DDR4 3600 MHz
Graphics Card(s)
ASUS ROG-STRIX-GTX1080TI-O11G-GAMING
Sound Card
Integrated
Monitor(s) Displays
2 x Samsung Odyssey G7 27"
Screen Resolution
2560x1440
Hard Drives
1TB Samsung 990 PRO M.2,
4TB Samsung 990 PRO PRO M.2,
TerraMaster F8 SSD Plus NAS
PSU
Seasonic Prime Titanium 850W
Case
Thermaltake Core P3
Cooling
Corsair Hydro H115i
Keyboard
Logitech wireless K800
Mouse
Logitech MX Master 4
Internet Speed
2 Gb/s Download and 100 Mb/s Upload
Antivirus
Malwarebyte Anti-Malware Premium
Browser
Google Chrome
Other Info
Logitech Z625 speaker system,
Logitech BRIO 4K Pro webcam,
HP Color LaserJet Pro MFP M477fdn,
APC SMART-UPS RT 1000 XL - SURT1000XLI,
Galaxy S23 Plus phone