if your idm 6.05 is expier then you can use this trick its 100 % work
DOWNLOD idm 6.052. Disconnect active connections to the internet.1. Exit IDM from the taskbar before entering the serial.
3. Then go to the directory C:\Windows\system32\drivers\etc and locate the file 'hosts'
4. Open the "hosts" file with "notepad".
5. on the last line enter the following address as shown and save.
127.0.0.1 www.internetdownloadmanager.com
7. your IDM is registered again.
8. No wonder you would be facing this problem again but without panic use a "new fake key" ( this time steps 3,4 and 5 are not required, the only thing required is "a keygen" for generating a new key. For IDM 5.14 Dr.Carbon Keygen is used ).
you can use this fake informatin
free serial number for internet download manager
Name - ahmedCompany - Madu Inc. mail - 123@gmail.com key - DWYNC-BCIYZ-UQSYO-9W3O3