Outlook 2003 is well known application of Microsoft Office which is the earlier version of outlook and launched before outlook 2007. Before the latest versions like outlook 2007, 2010, 2013 it was used by all outlook users and some of the users also use yet but it has less features than the latest versions. Sometime you became unable to add some .pst files while trying to add lots of PST files to e-mail profile in outlook 2003 and get the error message which is given for your better guide-
Outlook failed to add the personal store to the session.
There is a limitation of adding the PST file to the e-mail profile so if it passed the limit then in that condition or situation you will receive the error and can’t send or receive the e-mail. If you try to add more PST files to your e-mail profile through the option “Create or open outlook data File” then you may also receive the error but in this scenario the error message will different-
Out of memory or system resources, Close some windows or programs and try again.
Cause of this error:-
Adding more PST file to the e-mail profile is the cause of the error message “Outlook failed to add the personal store to the session”. Outlook 2003 require more memory for caching PST file than the earlier versions but if you enable the hotfix then it allocates the same memory as its earlier versions.
How to fix this error:-
If you want to fix the error while adding lots of .pst file to e-mail profile in outlook 2003 then you have to use the hotfix which is provided by Microsoft and contained in a service pack. If you are using the old version of outlook which is not updated then you have to install the hotfix but if you have installed the latest version of outlook 2003 then you have not to install the hotfix because it is already installed with this application. You have to do that enable the hotfix and set the UseLegacyCacheSize registry key and modify the registry key but it is compulsory to backup the registry file before modifying because it may be that by mistake you change the wrong setting then it be problematic for the system so the backup will help you. Follow the given steps to modify the registry-
i) If you are running outlook then close or quit it then click on Start and go to Run
ii) In the search box type “regedit”
iii) Go to the given registry Subkey
iv) From Edit menu click on New, DWORD Value
v) Write the “UseLegacyCacheSize” key and hit the enter button
vi) Now right click on this key and select the Modify option
vii) You will get the Value data box sp type 1 and press on OK
viii) Go to file menu and select exit to close the Registry Editor.
If you will follow the given steps then you can solve the problem of getting error message while adding more .pst files to e-mail profile of outlook 2003.