Can i limit an administrator account?

I have a pc running windows 7 ultimate 64 bit, and a friend of mine needs to use it. I have personal information on my computer that i do not want to be shared, and i understand that the easiest way to go about doing this is to make a standard user account. However, i will not be within 30 miles of this computer at any given time and i want said person to be able to install programs and such without me having to log in using remote support or giving them my password which would defeat the purpose of the standard user account. Is there a way to either give the standard user a few more privileges such as being able to install programs and things in that nature or being able to limit an admin account so my documents cannot be seen and i can restrict the use of cmd so said person cannot run control userpasswords2 and erase my password from their account giving them access to mine.
Any help is appreciated. If i have to il just do a dual boot and remove the os containing my account from the boot ini and partition the drive and encrypt my half. That would be the long way around though.

You cannot limit an admin account and all administrators are equal. Any restrictions you put in place any admin can alter or remove. All of this is by design and is basic to how Windows security works.

If you wish to restrict access to personal files the easiest way is to use NTFS encryption. This encryption is transparent to the user who encrypts the file and no one else will have access. Don't even consider doing this without having a backup of all your files. Of course you should have this anyway. Encryption is not completely secure when there are other admin accounts but far better than trying to limit an admin account.

I suppose in theory a limited account could be given the ability to install software. But unless you were a real expert the chances of success would be almost zero. Note that I said "in theory".