What is the best option?

possibly...if it is the body where the tabs are broken off the manufacturer (Olympus) might be able to replace the body shell. I'd check with them.

But it does not work.
Every battery cover of a camera has a switch, powering down the camera when the cover is opened. This is to prevent damage to the memory card. You should not remove batteries while the camera is writing to the memory card.
Find the little switch and press it. Then try to switch on.

When our lid broke (the plastic knob part broke from the rest of the plastic lid when my wife dropped it), I was able to glue it back on using Devcon "Weld it" adhesive. (Available at any hardware). So far it's held for over six years of regular use.

Otherwise you can always find use a glass replacement lid from Rival. I seen them going for $12 on Ebay (which included shipping). Look for 10-3/8" diameter, 5 quart.

According to Canon, camera communication is supported by Vista, like you have experienced. See:
http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&tabact=SupportDetailTabAct&fcategoryid=215&modelid=11209

The software that ships with the XT does not support Vista. To enable this support, you need to download an update from Canon. Click the following link and select Vista as your O/S from the drop-down box at the top:

http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&tabact=DownloadDetailTabAct&fcategoryid=314&modelid=11209

Note that there are also several updates there that you may want to download and install as well.

I loved my XT until my wife dropped it on vacation a couple months ago.

Hope this helps.
-Tor

Roughly about $60 and yes it can be repaired use the phone and ring around the camera shops That way you dont have to commit and can select the cheapest option

You will need to replace the battery cover assembly and contact Kodak at 1-800-431-7278 during normal business hours (Monday - Friday from 8 a.m. - 5 p.m. EST), and select option 3.

maybe you can do by yourself but its wise let technician to do it more knoledgeable to do it.

We have the same problem (white screen) after my wife took it on a trip. She had it in her carry on and didn't drop it.

It sound like the lens mechanism was damaged during camera's drop. Only way (to my regret)is to sent it to be repaired in a professional lab.