Cannot access own partition

[KAMANA]

I did some mistake and am in trouble and big problem now. Okay let me tell you in detail. I have one Hard Drive in my computer which has two partitions C and D respectively. C has Vista and other software's where as D has some of my personal documents and other stuff.
And there is a user account for my brother. And denied access for my brother to drive D as it has some personal stuff.
And I made some big mistake over here, I don't know how exactly to deny access. So what I did is I right clicked on the Partition clicked on properties then to security and I am not sure but maybe I checked-boxed denied access to everyone. I thought that "everyone" is everyone except me.
Now I can't access partition D:\ - it writes "access denied".
Please can some one help me out from this mess.?

[Sam.D]

Okay now over here you are actually in big trouble. You by mistake have given wrong permissions. And now you have to try many different steps to revert it back. Try this out, open Command Prompt and type "takedown /f d:" And make sure u are writing this under administrator.
If the command given above doesn't work then try to open Command Prompt "Run as Administrator" from the Accessories menu or else from the System32 in Windows folder.
Try all this options given.

[KAMANA]

I tried all the options given above nothing worked for me. I know I have tried it properly without making any mistake but still didn't work. Got the same error "Access Denied". I spoke to my friends they asked me to change the properties for the user through control panel. But that also didn't work.
Then I also tried System Restore, But same result. That also did not work.
Then I also tried to take ownership in Safe Mode. But that also didn't work.
I am clueless now. Don't know what to do. Please suggest some other solution.

[Glenny]

Okay now as you have tried many different things. Lets give a try to this. Just follow the steps given below and lets see if this works.
First Right click on the Drive which has problem that is D drive.
Then click on properties and in the properties window click on the tab that says "Security" and then click on the button that says "Advanced".
Then click on the "Owner" Tab, then click on edit then other users and groups.
Then click on the Advanced button and then click on find now.
Now in that list search for your username and click on it.
Then click on Ok and then again Ok on other window
Then you need to tick replace owner on subcontainers and objects.
And then last and final step click on Apply.
This had worked for me long time ago as even i had this issue and was resolved by following the steps given above.
Check if it works.

[KAMANA]

Now I just don't something so bad can happen with me. I followed the steps given but that did not work. Infact I was not able to complete those steps because when I right-click on drive d: there is no security tab, all the tabs are there but not the security. This is why I can't change anything.
Any other solution please.

[Macarenas]

I guess you have made some changes in registry for that security tab not to be there. Check your registry. Or else other safe option will be a fresh Vista installation on C drive and because of new installation all the permissions set on D drive will become void by default. So try it out.