I was running 2 accounts on that PC, each having his/her own Windows Live Mail individually. After the update WLM started in one account. In the other account it sort of freezes during startup and the processor uses 30% of its capacity for this start-up of WLM. Only via task manager I can stop this.

I tried to repair WLM via the Configuration Panel, This did not help. The I removed all WLM files in the user/apps directory an dinstalled again WLM without success. Is WLM not compatible with W8.1, or has anyone an idea to fix this?