My advice is: Don't install DX9 Beta or the ATI DX9 drivers, at this time, way too many problems! Also, forget the new 6200 drivers as well, various bugs & SmartGart problems for many setups. There are bound to be better (non-DX9) drivers released in the near future by ATI & much better MS-DX9 betas coming, with all the reported PROBLEMS. Both of these driver sets can HOSE your system, but OS System Restore & HD Imaging restore may not work in all cases either, to go back! Wait for the FINAL DX9 & hope the FINAL ATI DX9 drivers get the bugs corrected. (There is no rush for DX9 anyway, with current application/game non-support, except for a few.)
Some lucky souls are having no problems, it seems now, but once you go to DX9 drivers, forget about ever using non-DX9 drivers again, until you reformat. I love my Radeon, but I'm convinced ATI has made a mistake with the premature release of these particular drivers.
If you run WinXP & need to get rid of DX9: Direct X Eradicator doesn't work yet. (Author is working on future update for XP support.) Speculation is that Microsoft will include an Uninstall routine for a future DX9 beta release, due to reported problems. DX9 RC1( dx9.0.389.1) is released now, but still doesn't have an Uninstall routine.
Meanwhile, here is a DX uninstall package that works now, W2k/XP:
DX-Uninstall-W2K/XP ----Link is working most of time, but sometimes is down.
This one utilizes a safe approach, where you copy DX files from XP disk to a temp file, & then only while in SAFE mode, do you execute progy, which removes current DX, including DX9beta, & replaces with your original DX files.
One word of warning, even though this works for dealing with the DX9 files, if you installed DX9 beta & Radeon DX9 drivers, & had major problems, reverting to DX 8.1 will not necessarily solve all problems. Even the most aggresive (registry & fle search for remnants) uninstall of those Radeon DX9 drivers does not resolve certain issues. You may still need to reformat/reinstall XP, use the reliable 6193 drivers, to correct all problems.