Windows sets hardware acceleration to the maximum by default and disabling hardware acceleration will not cause problems at all.
In fact, you should disable hardware acceleration if you're capturing from the screen so that you can make sure that you can record anything that shows up on your screen.
On the other hand if you're about to start a live broadcast you should enable hardware acceleration because you'll get a better and smoother transmission. To record WMV and WMA files you should also enable hardware acceleration because Windows Media technologies take great advantage of hardware acceleration.
To disable or enable hardware acceleration open 'Global Options' or 'Record Settings' and you'll find a checkbox that enables or disables it.
If your OS is Windows 98 or Me then 1AVCenter won't be able to change the hardware acceleration but you can do it yourself going to Start/Control Panel/Video/Settings/Advanced/Performance and moving the acceleration slider as far to the left as you can.