Ask five users how long their PC takes to start and you get five different numbers, all of them wrong. Boot time is one of the easiest things in IT to measure exactly — so measure it.
Slow boot complaints start arguments because both sides argue from feelings. DEX settles them with two numbers per device: boot time and logon time, tracked in the Responsiveness pillar and trended over weeks. This guide shows the diagnosis order: split boot from logon, find the fleet pattern, hunt the usual stretchers — and know the honest limits of what the data can say.
👆 Boot and logon are separate problems with separate fixes (example figures)
The two numbers fail for different reasons. Boot time — power to the sign-in screen — is stretched by slow storage, too many startup services and drivers, and ageing hardware. Logon time — password to a usable desktop — is stretched by Group Policy processing, logon scripts, drive mappings to dead servers, roaming profiles and startup apps piling in. A PC can boot in 15 seconds and still waste three minutes after the password. Fixing the wrong half wastes the whole effort, so always read both numbers first.
One PC's 90-second boot means little until you know the fleet median is 20 seconds — or that every PC of the same model boots in 90. DEX trends and grouping let you ask the deciding questions: is this device an outlier (fix the device), is this model an outlier (fix the image or the model), or did everyone's logon time jump on the same morning (something central changed — a policy, a script, a server)? Each answer leads to a completely different job.
On a single PC you can cross-check without any tool: Event Viewer keeps a Diagnostics-Performance log under Applications and Services Logs > Microsoft > Windows > Diagnostics-Performance, where Event ID 100 records boot duration and the following events name the drivers and services that delayed it. Use it to confirm what DEX flags at fleet level — the fleet view finds which machines, the local log explains what inside one machine.
After the fix — SSD fitted, startup cleaned, dead drive map removed — do not declare victory from the spec sheet. Watch the device's boot and logon trend for a week and quote the result: "your morning wait went from four minutes to under one." Seconds are the currency users understand, and a fleet of small wins, each proven, is the strongest case an IT team can make for its refresh budget.
See the responsiveness numbers live in the video, then check your own fleet median — most teams are surprised by their real number.
▶️ Watch Full VideoOn a modern SSD-based office PC, under a minute from power to a usable desktop is a fair expectation, and many fleets sit near 40 seconds. Mechanical disks and heavy logon policies push it to several minutes. Judge against your own fleet median, not a marketing number.
A fleet-wide simultaneous jump almost always means a central change — a new or edited Group Policy, a logon script, a drive mapping to a struggling server, or a security agent rollout. Check what changed that morning before touching individual PCs.
Yes. Event Viewer's Diagnostics-Performance log records boot duration as Event ID 100, with follow-on events naming slow drivers and services. It is per-machine only — DEX's value is trending and comparing this across the whole fleet automatically.