# OS-10: Application Installation Requirements

Status: not started

Domain:
- 1.0 Operating Systems

Objective alignment:
- 1.10 Application installation requirements

## What You Need To Know

Application install questions are usually about compatibility and impact.

Before installing or upgrading software, check:
- OS compatibility
- 32-bit vs. 64-bit requirements
- CPU requirements
- RAM requirements
- Storage requirements
- Graphics/GPU/VRAM requirements
- External hardware token requirements
- Distribution method
- Impact to the device, network, operations, and business

## Memory Trick

Use **O-CRaSH-G-DIB**:

- **O**S compatibility
- **C**PU
- **Ra**M
- **S**torage
- **H**ardware token
- **G**raphics/GPU
- **D**istribution method
- **I**mpact
- **B**usiness risk

If the app will not install or runs badly, think:
- Wrong OS
- Wrong architecture
- Not enough RAM/storage
- Missing GPU/VRAM
- Missing driver
- Missing hardware token
- Bad source or corrupted installer

## Platform and Architecture

32-bit vs. 64-bit:
- A 32-bit OS cannot run 64-bit apps.
- A 64-bit OS can usually run many 32-bit apps.
- 64-bit Windows uses:
  - `C:\Program Files` for 64-bit apps
  - `C:\Program Files (x86)` for 32-bit apps

Driver compatibility:
- Drivers are OS-specific and architecture-specific.
- A driver for the wrong Windows version or architecture may fail.

## Hardware Requirements

CPU:
- Some apps require a minimum CPU generation, speed, or instruction set.

RAM:
- Apps may install but perform poorly if RAM is too low.

Storage:
- Check both install size and working data size.
- Some apps need much more space after install.

Graphics:
- Integrated graphics shares system memory.
- Dedicated/discrete GPU has its own VRAM.
- High-end apps may require dedicated GPU and minimum VRAM.

External hardware tokens:
- Some professional software requires a USB license dongle or hardware security key.
- If the token is missing, the software may not run.

## Distribution Methods

Download:
- Get from vendor or trusted app store.
- Avoid random third-party download sites.

Physical media:
- USB or optical disc.
- Less common now, but still possible.

ISO:
- Disk image file.
- Can be mounted by the OS and used like a virtual disc.

Image deployment:
- Installs a prepared system image, often with OS, drivers, and apps included.
- Common in business and virtual machine deployments.

Package managers:
- Linux examples: `apt`, `dnf`.
- Windows examples: Microsoft Store, winget in some environments.

## Impact Questions

Impact to device:
- App may slow the computer, break existing apps, overwrite files, or require reboot.

Impact to network:
- App may need internal services, firewall exceptions, bandwidth, or file share permissions.

Impact to operations:
- A workflow may change after an upgrade.
- A time-sensitive job may be interrupted.

Impact to business:
- Critical applications can affect revenue, customer service, compliance, or production.

Exam shortcut:
- If the app affects business-critical work, test first, schedule downtime, communicate, and have rollback.

## Commands To Enter

Windows:

```powershell
systeminfo
```

What it does:
- Shows OS, architecture, CPU, memory, and system details.

```powershell
wmic os get osarchitecture
```

What it does:
- Shows whether Windows is 32-bit or 64-bit.

```powershell
Get-ComputerInfo | Select-Object OsName, OsArchitecture, CsProcessors, CsTotalPhysicalMemory
```

What it does:
- PowerShell summary of OS name, architecture, CPU, and RAM.

```powershell
Get-Volume
```

What it does:
- Shows volume/file-system information and free space.

```powershell
winget --version
```

What it does:
- Shows whether Windows Package Manager is installed and its version.

```powershell
Get-AppxPackage | Select-Object -First 5 Name, Version
```

What it does:
- Shows installed Microsoft Store/UWP-style app package names and versions.

Linux:

```bash
uname -m
```

What it does:
- Shows system architecture, such as `x86_64`.

```bash
lscpu
```

What it does:
- Shows CPU details.

```bash
free -h
```

What it does:
- Shows memory usage in human-readable units.

```bash
df -h
```

What it does:
- Shows filesystem free space.

```bash
which apt
which dnf
```

What it does:
- Checks whether `apt` or `dnf` package manager commands exist.

macOS, if available:

```bash
sw_vers
uname -m
system_profiler SPHardwareDataType
```

What it does:
- Shows macOS version, architecture, and hardware summary.

## Mini Lab

Goal:
- Decide whether a computer can run a hypothetical app.

Hypothetical app requirements:
- 64-bit OS
- 8 GB RAM
- 20 GB free storage
- Modern CPU
- Dedicated GPU preferred
- Internet download from vendor site

Windows:
1. Run `systeminfo`.
2. Run `wmic os get osarchitecture`.
3. Run `Get-Volume`.
4. Optional: run `winget --version`.
5. Record:
   - OS:
   - Architecture:
   - RAM:
   - Free storage:
   - CPU:
   - Package manager available:
   - Meets requirements? Why or why not?

Linux:
1. Run `cat /etc/os-release`.
2. Run `uname -m`.
3. Run `lscpu`.
4. Run `free -h`.
5. Run `df -h`.
6. Run `which apt` and `which dnf`.
7. Record:
   - Distribution:
   - Architecture:
   - RAM:
   - Free storage:
   - CPU:
   - Package manager:
   - Meets requirements? Why or why not?

macOS, if available:
1. Run `sw_vers`.
2. Run `uname -m`.
3. Run `system_profiler SPHardwareDataType`.
4. Record:
   - macOS version:
   - Architecture:
   - RAM:
   - CPU/chip:
   - Meets requirements? Why or why not?

## Quick Check Before Quiz

You are ready for the OS-10 quiz when you can answer these without looking:
- Can a 32-bit OS run a 64-bit application?
- Which folder holds 32-bit apps on 64-bit Windows?
- What is an ISO?
- Why does VRAM matter?
- Why should business impact be checked before app updates?