I need to reinstall software of windows 7 computer and I lost my disks?

Two seperate issues. You can order new disks on ebay for example but if your product key is unreadable you need to purchase a new key.
See this link to buy - http://www.amazon.co.uk/Microsoft-Windows-Home-Premium-inkl/dp/B008OT79T4/ref=sr_1_2?ie=UTF8&qid=1426423337&sr=8-2&keywords=windows+7+coa

Sounds like you need to locate the proper driver for your CD drive. The windows XP driver won't work with Windows 7.

Hi,

Everyone mentioned some password recovery software, I too recommend you to use Stellar Phoenix password recovery software (http://www.stellarinfo.com/password-recovery.htm) . but I will advice you to first use manual methods of password recovery such as use windows installation disk or use "Offline NT Password and Registry Editor" to reset lost password.

Lost windows 7 passwords just isn't a serious problem. I know a fairly easy solution to recover lost windows logon passwords, just need to create a bootable disk or Usb memory card to recover forgotten windows password, I have made a bootable CD with the program Windows Password Seeker and reset my admin password successfully. You could Google windows password seeker or visit their site: http://www.passwordseeker.com

There is plenty of software that can reset forgotten windows password available online. I recommend Windows Login Recovery. Try this:

1. Enter a computer that can link to Internet. Download Windows Login Recovery and install the software on that computer.

2. Run the software and create windows password reset disk by follow the instructions.

3. Eject the created CD/DVD and insert it into the locked computer.

4. Reboot the locked computer (it's necessary for you to change your locked computer's BIOS setting to make it boot from CD drive) and then follow the instructions to reset your password.

5. Now login Windows and set a new password.