Outlook Login Problems

Fix Outlook Out of Memory Error When Signing In

Maira Mehtab Sep 24, 2026 870 views

Question details

The user is unable to sign into the desktop version of Outlook and encounters an "Out of memory or system resources" error message when attempting to change their password or log in.

Product: Microsoft Outlook
Device & OS: not provided
Scenario: Attempting to manually sign in to desktop Outlook or selecting the Change Password option.
Observed behavior: Outlook blocks access to email and displays an Out of memory resource message, preventing the sign-in process from completing.

Before you start

Before proceeding, ensure you save any open work and close background applications that consume high amounts of RAM, as this might be a genuine resource shortage. Performing a quick system restart can also naturally clear temporary system resource constraints.

Solution 1Recommended

Run Outlook in Safe Mode and Clear Cache

Starting Outlook in Safe Mode bypasses problematic add-ins that might be consuming excessive memory. Clearing the cache resolves errors caused by corrupted local data.

Often, third-party add-ins or corrupted temporary files trigger false memory errors in Outlook. Isolating the app in Safe Mode allows you to identify and disable the culprits.

Open the Run Dialog

Press the Windows key + R simultaneously on your keyboard to open the Run dialog box.

Launch in Safe Mode

Type outlook.exe /safe into the box and press Enter. If Outlook opens successfully, navigate to File > Options > Add-ins to disable any suspicious third-party add-ins.

Clear Outlook Cache

Press Windows + R again, type %localappdata%\Microsoft\Outlook, and press Enter. Locate the RoamCache folder and delete its contents to clear the cached files.

Data Safety: Clearing the RoamCache folder will not delete your emails, contacts, or calendar events. It only removes temporary load data.

Solution 2

Repair Your Microsoft Office Installation

A corrupted Office installation can trigger false out-of-memory errors. Running a quick or online repair often resolves underlying application issues.

Solution 3

Create a New Outlook Profile

If your current Outlook profile is deeply corrupted, the application may fail to allocate resources correctly. Creating a fresh profile bypasses this problem.

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If Microsoft Office applications continue to experience memory leaks or system resource errors on your device, consider switching to WPS Office. It provides a lightweight, highly compatible alternative for handling your documents, spreadsheets, and presentations without heavy resource demands.

1. Download the Installer: Visit the official WPS Office website and download the free installer package for your operating system.
2. Install WPS Office: Run the downloaded file. The lightweight installation process takes only a few moments to complete.
3. Open Your Documents: Launch WPS Office and instantly open your existing Microsoft Office files without worrying about compatibility or memory errors.

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Frequently Asked Questions

Why does Outlook display an 'Out of memory or system resources' error?

This error typically occurs due to corrupted Outlook profiles, outdated Office installations, conflicting third-party add-ins, or actual system memory limitations caused by having too many memory-intensive applications running in the background.

Will clearing my Outlook cache delete my personal emails?

No, clearing the Outlook cache (such as deleting files in the RoamCache folder) only removes temporary files used to speed up load times. Your emails, contacts, and calendar are safely stored on the email server or within your PST/OST data files.

What is the Microsoft Support and Recovery Assistant (SaRA)?

SaRA is a free diagnostic tool provided by Microsoft that helps troubleshoot and resolve common issues with Outlook, Microsoft 365, and Windows. It can automatically detect configuration problems and apply fixes for login and memory-related errors.

How can I increase Windows virtual memory to help Outlook run better?

You can increase virtual memory by navigating to Windows Settings > System > About > Advanced system settings. Under the Performance section, click Settings, switch to the Advanced tab, and click Change under Virtual memory to allocate more page file space. Note that this is generally recommended only for advanced users.

Outlook & Email Problems