The Other Windows Utilities: msinfo32, resmon, msconfig, cleanmgr, dfrgui, and regedit
Unit 2: Windows Tools, Commands, Settings, and Networking. Lesson 6 of 41 in APlus Academy Core 2.
Six more tools the objective names by their executable. Each answers one kind of question.
System Information (msinfo32.exe)
A read-only inventory of the machine: OS version and build, system model, BIOS or UEFI mode and version, Secure Boot state, processor, installed RAM, page file, hardware resources (IRQs, memory ranges, conflicts), components (display, storage, network with driver details), and the software environment (drivers, services, startup programs, environment variables). Export it to a file when a vendor asks for a system report, and use it to answer "is this machine in UEFI mode?" without rebooting.
Resource Monitor (resmon.exe)
Task Manager's Performance tab in detail, live: CPU by process and by service, memory (hard faults, working sets, the standby list), disk (which process is reading and writing which file, response time, queue length), and network (connections per process, listening ports, TCP throughput). Two things it does that nothing else does easily: show which process has a file open (search handles), and show which process is hammering the disk when the whole machine crawls.
System Configuration (msconfig.exe)
The boot and startup control panel.
- General: normal, diagnostic, or selective startup.
- Boot: choose the default OS on a multiboot system, timeout, and Safe boot (minimal, network, or alternate shell) so the next reboot enters safe mode without pressing keys; boot logging; no GUI boot.
- Services: enable or disable services, with "Hide all Microsoft services" so you can turn off everything third party in one step to find a conflict.
- Startup: now just a link to Task Manager's Startup tab.
- Tools: shortcuts to the other utilities.
Selective startup with all services disabled is the classic "clean boot" for isolating a crash.
Disk Cleanup (cleanmgr.exe)
Frees space by deleting temporary files, downloaded program files, the Recycle Bin, thumbnails, delivery optimization files, and, with Clean up system files, old Windows Update files and the previous Windows installation (Windows.old, which can be tens of gigabytes after an upgrade). Storage Sense in Settings automates the same cleanup on a schedule.
Disk Defragmenter (dfrgui.exe, Optimize Drives)
On a hard disk, files fragment into pieces scattered across the platters and reads slow down; defragmenting reassembles them. On an SSD, defragmenting is unnecessary and adds wear; instead Windows runs TRIM to tell the SSD which blocks are free. Optimize Drives knows the difference, shows the media type, and runs weekly on a schedule. Defragment an HDD that reports high fragmentation; never force-defragment an SSD.
Registry Editor (regedit.exe)
The registry is the database of Windows and application settings, organized in hives:
- HKEY_LOCAL_MACHINE (HKLM): settings for the machine, hardware, installed software, services.
- HKEY_CURRENT_USER (HKCU): the signed-in user's settings.
- HKEY_USERS, HKEY_CLASSES_ROOT (file associations), HKEY_CURRENT_CONFIG.
Keys hold values of types such as string (REG_SZ) and DWORD. Edit only with a vendor's instructions, and export the key first (File, Export) so it can be restored; System Restore also captures the registry. A wrong edit can prevent Windows from booting. Group Policy is the safer way to make the same change on many machines.
Which tool
- Is this machine UEFI with Secure Boot on? msinfo32.
- What is using the disk right now, and which process holds this file? resmon.
- Boot into safe mode next time, or clean boot to find a conflicting service. msconfig.
- Reclaim 30 GB after an upgrade. cleanmgr, system files, previous installation.
- A hard drive is slow after years of use. dfrgui, if it is an HDD.
- A vendor's fix says to change a value under HKLM. regedit, after exporting the key.
The Other Windows Utilities: msinfo32, resmon, msconfig, cleanmgr, dfrgui, and regedit, explained slowly
Six specialists
These utilities each do one job that the consoles do not. Learn the executable name, because the exam gives the name and asks the job, or gives the job and asks the name.
The table
executable name job the detail to remember msinfo32.exe System Information read-only inventory of hardware, firmware, drivers, software shows BIOS mode (legacy or UEFI) and Secure Boot state; export to a file resmon.exe Resource Monitor live per-process CPU, memory, disk, network which process has a file open; which process is hammering the disk msconfig.exe System Configuration boot options, safe boot, selective startup, services clean boot: hide all Microsoft services, disable the rest cleanmgr.exe Disk Cleanup delete temporary and leftover files Clean up system files removes the previous Windows installation dfrgui.exe Optimize Drives defragment HDDs, TRIM SSDs, on a weekly schedule never force-defragment an SSD regedit.exe Registry Editor edit the settings database HKLM machine, HKCU user; export the key before changing
msinfo32 in practice
The System Summary answers the questions that otherwise need a reboot into firmware: BIOS Mode (Legacy or UEFI), Secure Boot State (On, Off, Unsupported), BaseBoard model, installed physical memory, virtualization enabled in firmware, Kernel DMA protection. Components lists every device with its driver version and problem codes. Software Environment lists drivers, services, startup programs, and environment variables. Vendors ask for an NFO export.
resmon in practice
The Disk tab shows every process with read and write bytes per second and the files involved; the Response Time column exposes a dying disk. The CPU tab's Associated Handles search finds which process is locking a file you cannot delete. The Network tab's Listening Ports lists what is waiting for connections and which process owns it, the graphical netstat. The Memory tab's Hard Faults per second climbing means the machine is paging.
msconfig in practice
tab use General Normal, Diagnostic, or Selective startup Boot default OS, timeout, Safe boot (Minimal, Alternate shell, Network), No GUI boot, Boot log Services check Hide all Microsoft services, then Disable all: the clean boot; re-enable in halves to find the culprit Startup a link to Task Manager Tools shortcuts to the other utilities
Safe boot from here is how you get into safe mode on a machine that boots too fast to interrupt; remember to uncheck it afterward or the machine keeps booting to safe mode.
cleanmgr, dfrgui, and Storage Sense
Disk Cleanup's ordinary list frees a few gigabytes; Clean up system files adds Windows Update Cleanup and Previous Windows installation(s), which can free 20 to 40 GB after a feature update (and removes the ability to roll back). Storage Sense in Settings runs similar cleanup automatically. Optimize Drives shows each volume's media type; Analyze on an HDD reports fragmentation; Optimize defragments an HDD or sends TRIM to an SSD. A weekly schedule is on by default.
regedit, safely
hive holds HKEY_LOCAL_MACHINE machine-wide: SOFTWARE, SYSTEM (services, drivers), HARDWARE, SECURITY HKEY_CURRENT_USER the signed-in user's settings; a view into HKEY_USERS HKEY_USERS every loaded user profile HKEY_CLASSES_ROOT file associations and COM classes (merged view) HKEY_CURRENT_CONFIG the current hardware profile
Values: REG_SZ (text), REG_DWORD (32-bit number), REG_QWORD, REG_BINARY, REG_MULTI_SZ, REG_EXPAND_SZ. Before any change: File, Export the key (a .reg file), or create a restore point. A .reg file double-clicked merges its contents into the registry, which is how vendors distribute fixes and how malware distributes persistence. Group Policy sets registry values under the hood, so prefer it for many machines.
Worked examples
- A vendor says "your system must be in UEFI mode with Secure Boot on." msinfo32 shows Legacy and Unsupported: the disk is MBR; convert with MBR2GPT and switch the firmware.
- A file cannot be deleted because it is in use. resmon, CPU tab, Associated Handles, search the file name, end the process.
- An application crashes only on one PC. msconfig clean boot; it works; re-enable services in halves; the culprit is a third-party audio service.
- A laptop's 128 GB SSD is full after the Windows 11 upgrade. cleanmgr, system files, previous installation: 25 GB back.
- A five-year-old desktop with an HDD is slow to open files. dfrgui shows 30 percent fragmented; optimize.
- A support article says set a DWORD under HKLM\SOFTWARE\Vendor. regedit, export the key first, add the value, restart the service.
How the exam asks it
- "Which utility shows whether Windows is booting in UEFI mode?" System Information (msinfo32).
- "Which tool identifies which process is using a file?" Resource Monitor (resmon).
- "Which tool configures the PC to boot into safe mode on the next restart?" System Configuration (msconfig).
- "Which tool removes the previous Windows installation to free space?" Disk Cleanup (cleanmgr).
- "Which tool should not be used to defragment an SSD?" Disk Defragmenter (dfrgui optimizes with TRIM instead).
- "What should be done before editing the registry?" Export the key or create a restore point.
What to memorize
- The six pairs: msinfo32 inventory and firmware mode; resmon live per-process and handles; msconfig safe boot and clean boot; cleanmgr temporary files and Windows.old; dfrgui HDD defrag and SSD TRIM; regedit hives, export first.