Hi @Bettina4you,
You need a large pagefile.sys to make up for the lack of RAM memory
see Can’t create C++ project ( or use C++ ) - Unreal Engine 5 Early Access / Feedback for Unreal Engine 5 Early Access - Unreal Engine Forums
In this case, I used 32GB, but now with the current version you will need 64GB to achieve that speed and make sure the UE5 is on the SSD drive and you drives have been trimmed and fragmented.