Restarting pc usually helped me with this issue

It's doesn't work.

Ty for help Though!

Two possible solutions:

1) Do you maybe installed Classic and LoD in two different languages? For example: German version of Classic, English version of LoD? If so, install same languages only.

2) Go to: Control Panel System Advanced System Settings Settings (Performance) Advanced Change It should look like this: http://s1.directupload.net/images/110726/8a373htt.png

In that window (Virtual Memory), uncheck the very first line (it's checked in the screen). Below it, select the drive where Diablo 2 is installed. Now you need to edit the Custom Size: Change both the Initial Size and the Maximum Size to the Recommended Size (which is on the bottom - 3069 on the example picture).
Apply the changes and restart your computer. Now check if Diablo 2 works properly.

I install classic in German and lod in English..
ty for the help!!!!!!!!!