2004 525i
when i turn the key, nothing happens, not even the solenoid clicking
all electronics works as normal, means cant be battery...

 

just tried disconnecting and reconnecting the battery.. did nothing but made steering errors

 

That sucks. Welcome to the "my E60 won't start" club.

Sounds like you need to get that bad boy to a mechanic ASAP.

 

If your clutch/brake safety switch has failed you should get an indication on your display at start up.
If I understand the Battery Safety Terminal, it can disconnect the starter/alternator, and still leave power to the electronics. (usually in the event of an accident) http://www.rfdm.com/tis/12_42_540.pdf
Failing batteries seems to be epidemic. Maybe the battery voltage is too low to engage the starter. Will it jump start?
GL and don't get frustrated!

 

i tried jump starting it didnt work
maybe i didnt jump start it correctly? i connected the positive to the positive terminal on the engine bay and the negative to that "special nut" near it

 

Time to call roadside assistance.

 

Sounds like you did it right. Maybe starter or loose connections to it. I haven't seen an electrical diagram for these cars and not sure about a starter relay in the system.
Scott may have the best advice...Roadside Assistance. Although in his thread yesterday melimel mentioned a hammer to the starter....

 

where is the relay situated anyway?