I am not able to downgrade the 1252G to Autonomous Access point. First I try with IOS image c1200-k9w7-tar.123-7.JA5.tar
I rename it to -tar.default and upload the IOS after the upgrade I am gettting this error and AP has stuck
File "flash:/c1200-k9w7-mx.123-7.JA5/c1200-k9w7-mx.123-7.JA5" uncompressed and installed, entry point: 0x3000
Please help me out who to solve this problem and which another IOS should i have to try.
You are on the right track here :) You will need a newer IOS like 12.4(10b)JA
Release Notes for Cisco Aironet Access Points for Cisco IOS Release 12.3(7)JA5
You can install Cisco IOS Release 12.3(7)JA5 on all 350, 1100, 1130AG, 1200, 1230AG, and 1240AG access points.
Release Notes for Cisco Aironet Access Points and Bridges for Cisco IOS Release 12.4(10b)JA
You can install Cisco IOS Release 12.4(10b)JA on all 1130, 1240, 1250 series access points, 1300 series outdoor access point/bridges, and 1400 series bridges
Hope this helps!