"system suddenly using massive data - where and what for?

Question

"system suddenly using massive data - where and what for?

Carol Morgan 0

I have not used much data previously Never came close to 110 GB - usually less than around 65GB. Since June I get messages I am blowing my monthly data allowance in 24 hours. Under usage it says "system" is using 150+GB every 30 days - how do I find out what that is about and where my data is going and why? My usage hasn't changed. I don't game or stream and cannot understand the massive sudden change

Sandra de Bruijn 0 Reputation points

2026-05-23T11:58:19.65+00:00

I think because Microsoft is using our memory space for other users, what better way than peer to peer? because I also have enough memory and as they using sync for pc's and mobile phones, we should have more than enough, but I also get often a message I should buy more Cloud space.

2 answers

Your answer

Sandra de Bruijn 0 Reputation points

2026-05-23T11:58:19.65+00:00

I think because Microsoft is using our memory space for other users, what better way than peer to peer? because I also have enough memory and as they using sync for pc's and mobile phones, we should have more than enough, but I also get often a message I should buy more Cloud space.

Answer 1

I've followed those steps and not able to resolve the issue.

As mentioned the data use in step 1 - says data being used in "system"

Optimisation - Step 2 (is on) info seems to suggest that would use less data rather than more so I'm unsure how turning it off will make a difference or what might happen if I do - I only have a PC, laptop and mobile.

Step 4 - task manager - nothing indicating use is above very low on any items in the list

Any ideas what else "system" might entail and be using data on? Is there any way to find out a history of usage under "system" to figure out what and when it might have happened.

Answer 2

Dear Carol Morgan,

Thank you for reaching out regarding the unexpected increase in data usage reported on your device. We understand how concerning it can be to receive alerts about exceeding your monthly data allowance, especially when your usage habits haven’t changed.

Based on your description, it appears that the “System” category is consuming a significant amount of data—over 150 GB in 30 days—which is highly unusual for typical background activity. Let’s walk through a few steps to help identify and address the cause:

Recommended Steps to Investigate and Reduce Data Usage:

Check Data Usage Breakdown Go to Settings > Network & Internet > Data Usage. Select your network (Wi-Fi or Ethernet) and review which apps or services are using the most data.
Review Windows Update Activity Large updates or repeated downloads can consume significant bandwidth. Go to Settings > Windows Update > Update History to check for frequent or failed updates.
Disable Delivery Optimization Windows may use your device to share updates with other PCs. Go to Settings > Windows Update > Advanced Options > Delivery Optimization and turn off “Allow downloads from other PCs.”
Scan for Background Services Use Task Manager or Resource Monitor to check for background processes that may be syncing or downloading data.
- Pay attention to services like OneDrive, telemetry, or third-party apps.
Run a Malware Scan Unexpected data spikes can sometimes be caused by malicious software.
```
  Run a full scan using Windows Defender or your preferred antivirus solution.
```

IPlease let me know if any of these steps help resolve the issue. If you find this answer helpful, feel free to hit "Accept Answer" so others can benefit too 😊. T&B, Domic Vo.