Quick answer
Open Excel in Safe Mode (hold Ctrl as it launches, then click Yes). If it behaves in Safe Mode, an add-in is the likely cause — turn your COM add-ins off one at a time. If it still crashes, turn off hardware graphics acceleration, make sure Office is fully updated, then run an Office Quick Repair.
WHY IT HAPPENS
It's rarely the spreadsheet's fault.
Most Excel freezes come down to one of a few things: a third-party add-in misbehaving (accounting, PDF or reporting tools are common offenders), an out-of-date copy of Office, hardware graphics acceleration clashing with your video driver, or a genuinely heavy workbook full of volatile formulas. Safe Mode is the fastest way to split "it's an add-in" from "it's something else" — so start there.
THE FIX
Work through these in order.
- Open Excel in Safe ModeHold the Ctrl key while Excel opens and keep holding until it asks if you want to start in Safe Mode — click Yes. (Or press Windows key + R, type excel /safe and press Enter.) Safe Mode loads Excel with no add-ins or custom settings, so if it's stable here, one of those is your problem.
- Disable COM add-ins one at a timeGo to File → Options → Add-ins. At the bottom, set Manage to COM Add-ins and click Go. Untick one add-in, click OK, then reopen Excel normally and use it as usual. If the crashes stop, you've found it — leave that one off or ask the vendor for an update.
- Make sure Office is fully updatedIn Excel go to File → Account → Update Options → Update Now. A lot of freezing and crashing bugs are fixed in later updates, so getting current is one of the highest-value steps and worth doing before you dig deeper.
- Turn off hardware graphics accelerationGo to File → Options → Advanced and, under Display, tick Disable hardware graphics acceleration. Excel uses your video card to draw the screen, and an older card or driver can cause flicker, blank areas and crashes. This one fixes a surprising number of cases.
- Check for a large or volatile workbookIf it's one specific file that hangs, the file may simply be doing too much — huge ranges, whole-column formulas, or volatile functions like TODAY, NOW, OFFSET and INDIRECT that recalculate constantly. Trim unused rows and columns, remove stray formatting, and switch calculation to Manual (Formulas → Calculation Options) while you edit.
- Update your graphics driverEven with acceleration off, an outdated video driver can cause instability. Update it from your PC maker's support site or the graphics chip vendor (Intel, NVIDIA or AMD), then restart and test again.
- Run an Office Quick Repair, then Online RepairIn Windows Settings → Apps → Installed apps, find Microsoft 365 / Office, choose Modify → Quick Repair. If the problem survives that, run Online Repair — it's slower and needs internet, but it reinstalls Office cleanly without touching your files.
Still crashing after all that? If Excel keeps falling over — or the same happens across several staff — the cause is usually deeper: a bad add-in rolled out to everyone, an ageing PC, or a corrupt Office install that needs a proper reinstall. That's the point to bring in your IT provider rather than losing more hours to it machine by machine.
