F520 unable to access any opration

This means that the operating system on the hdd fails to start.
The hdd is probably failing and needs replaced.

Download the software directly into your laptop and then run it.

Operating system start error
reinstall the HDD software

did you formatt the HDD.if so,you will have to reload firmware.This is an operating system start error.

the problem most probable is the win xp os that you are using
Microsoft has stopped maintaining win xp quite some time ago and the operating system is failing when changes are made to the extras in use
Talk with a computer repair shop for advice

Don't try to enter a PUK code without knowing the right one. You need to call your service provider to get this code. It can be as many as 8 digits, and it is random. If you enter too many wrong codes, you can permanently damage the device. So Please You Go to Service office and Get the Duplicate Sim From Office Oprater Same Your No Problem will Solved

go to the device manager then under cd/dvd drives, right click to the driver then click on uninstall.. restart the computer then it will reinstall automatically

fuser p/n DA7A013A4X

OK you can certainly add wireless to this machine. But be careful which type you buy. If this machine has windows 98 you have to ensure the wireless adaptor will be compatible. . you have two choices for the adepter type either USB or PCMCIA (aka PC Card) I'd go for the PCMCIA version, it will be more likely to play well with the older system. Also, Dont buy a MIMO card, a simple 802.11B or 802.11G compatible card will work. these are in the sub $40 price.

Dont attempt to install XP or VIsta on this PC, it will be unbearably slow. Stick with 98 or better yet windows 2000.

-Good Luck

the operating system files have got corrupted if you have the option on the screen when you first turn it on to go to recovery ,usualy F11 it will recover the software ,if not you will need to install the o/s again
good luck
Terry