Dell's article on a slow computer lists the causes: fragmented data on a hard disk drive, unused programs running in the background, outdated drivers for chipset, BIOS and docks, outdated or corrupt Windows files, a configuration that does not meet the needs of demanding apps or games and insufficient memory. Its recommended first steps are to disconnect devices such as printers and docks so you can tell laptop from accessory, optimize the system with SupportAssist, restart (which clears memory and shuts down errant processes) and run a hardware diagnostic. On Dell's thin laptops the memory is soldered (the XPS 13 uses 8 to 64 GB LPDDR5x and cannot be upgraded), so a machine bought with too little memory has to be managed by closing apps rather than adding RAM; the Latitude 5450 and Alienware m16 R2 use upgradeable DDR5.
Differential
Likely causes of “Dell laptops is running very slowly”, and how to tell them apart
- 1
Programs running in the background
What separates it The laptop is slow right after login and speeds up when you close apps
How to confirm Dell lists unused applications running in the background; disable startup programs and close what you do not need
- 2
Outdated drivers or BIOS
What separates it Slowness began after a Windows update, or the dock and graphics lag
How to confirm Dell lists outdated drivers for chipset, BIOS and docks; update with SupportAssist or Dell Command Update
- 3
Insufficient memory
What separates it Many apps or browser tabs and the laptop stalls when switching
How to confirm Dell lists insufficient RAM; soldered-memory models cannot be upgraded, so close apps or reduce tabs
- 4
A full disk
What separates it Slowness as the drive nears full, with low disk space warnings
How to confirm Free space with Disk Cleanup or Storage Sense, as Dell's storage article describes
- 5
Corrupt or outdated Windows files, or a hardware fault
What separates it Slowness with freezes or errors after every step above
How to confirm Run SupportAssist optimization and the hardware diagnostics; Dell lists both
Before you touch a setting
Record this first — changing settings destroys the evidence
- Which Dell laptop you have, its memory and drive, Service Tag and BIOS version
- Which actions are slow (boot, apps, browser) and the top processes in Task Manager
- Free space on the C: drive and the SupportAssist optimization and diagnostic results
- Whether a dock or other device is attached and whether the fan is loud
Try in this order
0 of 7 completedDisconnect devices
ReversibleDisconnect devices, by removing docks, printers and drives, as Dell recommends, then testing the speed.
Restart
ReversibleRestart, to clear memory and errant processes, as Dell's article says, and test again, and then test again to see whether it helped.
Optimize with SupportAssist
ReversibleOptimize with SupportAssist, by opening SupportAssist, Troubleshooting and diagnostics, and running System Optimization, and then test again to see whether it helped.
Check startup programs and Task Manager
ReversibleCheck startup programs and Task Manager, by disabling unnecessary startup items and ending heavy processes.
Update drivers and BIOS
ReversibleUpdate drivers and BIOS, by installing chipset, graphics and BIOS updates from SupportAssist or Dell Command Update.
Free disk space
ReversibleFree disk space, by running Disk Cleanup or Storage Sense, and see the storage page for more.
Run hardware diagnostics
ReversibleRun hardware diagnostics, by pressing F12 and running the drive and memory tests, and noting any error codes.
Model-specific
What is true of this model and not of its siblings
- Memory by line
- XPS 13 9340: 8 to 64 GB soldered LPDDR5x. XPS 14 9440: 16 to 64 GB LPDDR5X. XPS 16 9640: up to 64 GB soldered. Latitude 5450: 8 to 64 GB standard DDR5. Latitude 7450: 16 or 32 GB soldered. Inspiron 14 5440: 8 to 32 GB DDR5. Alienware m16 R2: 8 to 64 GB upgradeable DDR5.
- Chips
- XPS 13 and 14: Intel Core Ultra. Inspiron 14 and 16: Intel Core 7 150U or Core 5 120U. Latitude: Core Ultra vPro. Precision 5690: Core Ultra with NVIDIA RTX Ada options. Alienware m16 R2: Core Ultra 7 or 9 with RTX 4050 to 4070.
- Repair cost
- Slowness is usually startup apps, storage or updates and costs nothing to fix. A drive replacement is $99 to $179 per BadgerLayer's 2026 PC repair guide, and data recovery from a failing drive starts at $149, per BadgerLayer's 2026 laptop repair guide.
- Other models this page answers
- These steps also fit models XPS 14 9440, XPS 16 9640, Inspiron 14 5440, Latitude 5450, Latitude 7450, R2.
Stop boundary
When this stops being a self-service repair
- !If hardware diagnostics fail the drive or memory test, contact Dell Support
- !If the laptop is slow with a healthy drive, free space and updated drivers, back up and consider a reset through SupportAssist OS Recovery
- !If slowness comes with loud fans at idle or swelling signs, see the heat and battery pages
Evidence ledger
Sources behind this answer
Causes, disconnecting devices, SupportAssist optimization, restart and hardware diagnostics.
Fast Startup and driver notes that can affect responsiveness.
Disk Cleanup and Storage Sense.
The XPS premium laptop line.
The Latitude business laptop line.
Exact questions
Common questions
What does Dell list as causes of a slow computer?+
Fragmented data on a hard disk drive, unused programs running in the background, outdated drivers, outdated or corrupt Windows files, a configuration that cannot handle demanding apps, and insufficient memory.
Can I add RAM to a Dell laptop?+
It depends on the model. The XPS 13 has soldered LPDDR5x memory that cannot be added, while the Latitude 5450 and Alienware m16 R2 use standard DDR5 modules.
Does a restart really help?+
Dell says a restart clears memory and shuts down errant processes and services; the more programs open and the longer they run, the more likely the laptop slows.
What is SupportAssist System Optimization?+
Dell says it runs tests and diagnoses settings on the system to improve performance.
Does the slow laptop need a new drive?+
Only if the hardware diagnostics report a drive fault. Free space, drivers and startup programs come first.
Do gaming and workstation laptops slow down differently?+
They slow under heat: Dell says most processors reduce speed to compensate for heat, so keep vents clear and use a hard surface.