Privilege Issues

[Vivek788]

I recently re-installed Windows XP.
I had serious issues with errors coming up saying I don't have enough privileges to install.
This happens with any software install that involves the C:\ partition.I am just fed up,this went a long way and my bro somehow fixed it by using lots of fix packs,registry edits and registry fix tools.Finally he had to restore to older position before an Autopatcher install to get some control back.
Now again,while trying to install Yahoo Messenger,I am getting same error.I tried to run setup with Run As option,still same problem.Also I am the admin user.
My bro says that it might be because I installed new windows over old by just doing quick format.
Can someone comment on the situation,possible routes,reasons?
Can a proper install with full format fix the problem?

 

[blueshift]

Do you have any idea about applying Security permissions to drives or folders/files?
If not then search in google

Regards,
blueshift

 

[Roadripper]

My bro says that it might be because I installed new windows over old by just doing quick format.

Can a proper install with full format fix the problem?

Using quick format doesnt create th error .. chek ur user accounts to c if u hav al teh admin priviledges... how many accounts u hav ...

 

[kin.vachhani]

can be a problem of virus too..which revoke your previledges from account.

 

[meghdut]

Check whether your account still has the administrator privilege. Before logon press ctrl+alt+del twich and login as computers default administrator account, which xp provides regardless of whether you have an administrator account created or not. There you can check the privileges of your account and make changes accordingly

 

[Vivek788]

I have only one account.
On trying to switch users,I get only one user which is myself,the administrator.
I too feel it's some virus job,maybe because I was late in installing proper protection,even now I don't have a firewall.This occured because I was using an original version of McAfee which was not renewed later and now I use free McAfee services.My IE seems to go to a 'demonsearch.com' by default,even though I have tried to change it.
I also use Spybot Search&Destroy,but nothing has been caught so far.

 

[Vivek788]

I formatted fully and reinstalled windows.I have same problem.But I didn't see it while installing any software.It came when I modified the Startup items.In spite of me being denied access...all the changes were reflected after reboot.