Why Backupexec crashes if you restart server ?

Hello!

Can someone explain it to me, why Backupexec 2010 R3 crashes when windows installs updates and then restarts itself while jobs are running ?
The same happens if you manualy restart server while jobs are running.

If you are lucky, simple service restart helps, if you arent u have to reinstall the backupexec.

Happens on win 2003 servers

Happens on win 2008 servers  

Happens on win 2012 servers. 

I dont get it, The program costs a lot of money and it can`t survive simple server restart.

I`m responsible for more than 30 servers with backupexec and its always the same. If Backupexec doesn`t work check when the server was restarted and in 95% of cases the reason for backupexec fail is server restart.

Best regards

Andrej