You can create a limited (regular) user account for him.
Only Administrators can format disk drives.
Therefore he won't be able to format a drive. Formatting USB drives also requires Administrator privileges.
There are no special privileges for formatting in Windows: all or nothing. So you can't select drives where formatting is allowed.
Beware: non-Administrator user account imposes other restrictions as well: installing software (desktop), changing global system settings…
Update:
I was thinking about other ways on how to prevent drive formatting. (Although these options are more about making it harder to see the drive, as a side effect you get the bonus of preventing formatting.)
- Hide the drive from Explorer, as User suggested. The drive is not visible in Explorer interface but it's accessible through the system. Other application may show it. And you can easily get access to it: type
D:\
in the address bar, and here you go.
- Hide the drive entirely, remove drive letter association.
- Click Manage in the context menu of Computer.
- Select Disk Management in the list of options on the left.
- Right-click the box with drive
D:
(or any other) and then click Change drive letter and path.
- Select
D:
and click Remove button.
To restore it, click Add and assign a drive letter.
- Remove Format command from drive context menu. Yet I haven't found a way to do it.
When you remove drive letter as described in option 2, no one can access the drive in Windows. You have to add a drive letter to use it.
Yet there's alternative: you can mount the drive into a folder.
In the dialog from step 2.4, click Add, click Mount in the following empty NTFS folder, and type the path to the folder or click Browse to select it.
This way the drive can't be accessed via a drive letter (if it's unassigned of course), but all the data from the disk is visible in the folder.
6A backup(!) solution would be to take regular backups. Then, if he does format the wrong drive again you can restore your data. It will also guard against theft and damage to your drives as well – ChrisF – 2012-11-02T13:07:57.343
8Beat him severely and break all his fingers... that should fix it... oh and like @ChrisF regular backup would be the best option – TheXed – 2012-11-02T13:13:40.043
1Set up a guest account. And do not belittle your brother in public as someday you may deeply regret every disparaging thing you've said about him. – Snesticle – 2012-11-02T13:18:41.617
3If he has physical access to the computer you can't stop him. Whatever walls you erect on Windows, he can simply bypass them entirely with a Linux live CD/USB. – badp – 2012-11-02T13:18:49.573
snesticle - He deserves it! Even he feels stupid at what he did. badp - He does not know about Linux, only Windows. – Jörg – 2012-11-02T13:24:38.743
@badp That's true. But this makes it harder. Additionally, the BIOS could be password-protected so that he won't be able to change the boot order to boot from CD/USB. – Alexey Ivanov – 2012-11-02T13:27:12.047
@AlexeyIvanov Nothing a good ole magnet can't fix :) – badp – 2012-11-02T13:37:43.313
You can recover the data easily: http://www.partition-tool.com/ http://www.piriform.com/recuva
– Elmo – 2012-11-02T17:11:37.3802@User: Recuva is not a magic bullet. There are a whole host of factors that might interfere with data recovery after a format, incuding how much he has used the drive/partition since then. As ChrisF said, nothing makes you a believer of regular backups like data loss! – Karan – 2012-11-02T17:32:40.770
There is no protection against stupidity, except that we all die eventually, hopefully not at the hands of some stupid person... – Moab – 2012-11-02T18:16:20.960