I get “Out of memory” error when repairing a PST/OST file. What to do?

This error means your PST/OST file is too large and the memory space in your system is insufficient for recovering it. In general, this error occurs on some low-end computers, and the PST/OST file is larger than 50GB.

Here are some solutions for “Out of memory” error:

  1. Install our product on another computer with better hardware configurations and try again. It is recommended to use a 64bit computer with more than 64GB memory and 64bit Outlook installed to do the task. For 64bit Outlook, you can use 64bit DataNumen Outlook Repair/DataNumen Exchange Recovery which will fully utilize the memory in your system.
  2. Make sure there are enough free disk spaces in your C: drive. Windows will use the disk spaces in C: drive as virtual memory. If there are not enough free disk spaces on C: drive, then you will also encounter such a problem. It is recommended to keep at least 100GB free disk spaces on your C: drive.
  3. Or you can use DataNumen File Splitter to split your PST/OST file into several pieces, each for about 10GB size. Then run DataNumen Outlook Repair/DataNumen Exchange Recovery to repair these PST/OST files one by one or in batch via the “Batch Repair” function. However, with this solution, you may lose some data when splitting your PST/OST file and some emails are in the boundary of the file, but you can prevent “Out of memory” error occurs and recover most of the data.