Windows 7: Don't have administrator access. Want to defrag and install new progra

I am using a laptop with following sepc:

ThinkPad lenovo laptop, T410i
Windows 7 Professional 64bit

This laptop is companie's one and I am using at home.
I don't have administrator access and neither I have the password for administrator.
Company has defined a user account for me and I only can log on with it.
I think these steps are for security reasons not to crash the laptop.

Now that I want to defrag the computer, it asks me to login as administrator account.
Or I want to install a new program and I can't. This is very annoying.
Is there any way to install only in my own user account?

When I explained the matter to IT officer in the company, she told that I should take the laptop to the company and they will take care of the issue.
BTW the head office is 600 km away.

BR
Yabi

While I understand your frustration, the bottom line is it is a work computer, and their rules. You may have better luck contacting the home IT department and ask them, rather than your local IT people ... Good Luck!