Restore latest kernel

[Mike Adolf]

This morning I ran the latest Ubuntu update.  It installed a new kernel 
2.6.24.21.  I rebooted and all was well.  Then I installed my new pctv 
800i tuner card. To do so, according mythtv wiki, I first extracted 
firmware from a windows file and placed it into 
/lib/firmware/2.4.24.21-generic, I downloaded the latest v4l driver 
tree, did a make and make install. This is supposed to overwrite kernel 
drivers. When I tried to reboot modprob failed.  It also failed in 
recovery mode.

Can I some how remove the corrupt 2.4.24.21 kernel, so that auto update 
reinstalls it? I an new booted into 2.4.24.19.

Thanks,
Mike