How to Move Outlook from C Drive to D Drive
Some users may find that Outlook takes too much disk space on the C drive and wish to move it to another drive. If you also face this problem, this post will show you how to solve it and some tricks to extend C drive space.
Overview of Outlook usage on C drive space
Microsoft Outlook is a comprehensive personal information manager primarily used as an email application. It is developed by Microsoft and is part of the Microsoft Office suite. Outlook is widely used in both professional and personal settings due to its range of features and integration capabilities. Users can easily manage their emails, schedule tasks, etc.
To smoothly run on your PC, Outlook required for the installation of Microsoft Outlook varies slightly depending on the version and specific updates. Generally, the Outlook application itself requires approximately 2-3 GB of disk space on the C drive. But, for data storage, Outlook may require for moderate email usage, expect anywhere from 1-10 GB or more.
▍ Email Storage: The amount of disk space Outlook uses on the C drive for email storage depends significantly on the volume of emails and attachments you receive and store.
▍ Outlook Data Files (PST/OST): Outlook stores emails, calendar entries, contacts, and other data in Personal Storage Table (PST) or Offline Storage Table (OST) files. These files can grow quite large, sometimes several gigabytes, depending on your email usage.
▍ Updates and Patches: Regular updates and patches from Microsoft can add to the disk space requirements over time.
So, for most users, a total of 5-15 GB is a reasonable estimate for Outlook's disk space usage on the C drive, combining installation, data storage, and cached files.
How to move Outlook from C drive to D drive without data loss
If you want to move Outlook to another drive, you can't simply copy and paste like a data file transfer because program boot requires many other relevant files. So, to make sure the moved app can run as usual, the safest method to move Outlook is to choose the App Moving tool.
AOMEI Partition Assistant Professional is a robust disk management software. With just a few keystrokes, you can transfer programs and applications, such as Microsoft Office, OneDrive, and games, from their current location to another drive (e.g., from the c drive to the d drive or from an internal drive to an external drive) without any data loss.
You can select multiple programs or applications and transfer them simultaneously. Furthermore, in addition to the program's movement feature, this software enables the allocation of free space from one drive to another, disk cloning, and partition merging.
100% SecureStep 1. Install and launch AOMEI Partition Assistant Professional on your computer. After that, disks and partitions’ info will be displayed on your screen.
Step 2. Follow “Free up” > “App Mover”.
Step 3. In the App Mover window, select the C drive where Microsoft Office is and hit “Next”.
Step 4. Tick Word, Excel, and PowerPoint and select another drive as the destination drive. Hit “Move”.
Step 5. Hit “OK” to confirm the prompt and then, the program transfer will start.
Step 6. After it’s one, click on “Finish”.
Now, navigate to the location where moved Microsoft Office is and check whether it runs smoothly. If it can’t be launched successfully, you can use the restore feature to send it back to its original location.
Further reading: Move Outlook files to D drive
“Cannot move OST file from default to D drive – Outlook wants PST file instead.
The version of Outlook I use is Office 365. The data file is an OST file that is 10GB big and taking up a lot of space on my C drive in the usual spot of C:\Users\user\AppData\Local\Microsoft\Outlook. I want to move this file to the partition D: that has a lot of free room. One of the "expert" blogs told me about a register hack that I tried. It didn't work. Another "expert" blog told me to move the file and change the usual path, so I did that. This method told me that the OST file is not an Outlook data file and that I needed to choose a PST file, which I did not do. Is there a way to do this that works?"
--Microsoft Community
As we mentioned, Outlook will need more than 10GB disk space to save your data, so, if your Outlook data folder become large agian after your move app, you can relocate this folder to another drive. But, just as the case mentioned, some users may noy be able to move Outlook folder. In this case, you can try "Move Folder" function of AOMEI Partition Assistant Professional.
This feature can move your data folder such as the Profile folder, C drive default Document folder... from C drive to D drive. The operation is very simple and it's similar to App Mover. You choose “Move Folders” after you enter App Mover function, you can perform folder moving: select the folder to move. Then, select the new drive and click Move, then click OK to start the process.
To sum up
If you're stuck in trouble with how to move Outlook from C drive to D drive, hope this post can solve your problem. AOMEI Partition Assistant will help you safely and effortlessly move installed apps. Besides moving apps, if your disk has more than one partition whose drive space is sufficient, the "Allocate Free Space" function can also adjust your C drive space via extending your C drive with that space. What's more, there is the Server edition of this practical tool for Windows Server 2025/2022/2019/2016/2012.