The latest usb driver of nokia 5800 has been released and simple downloading link is available for download. Nokia developers releasing USB drivers of its all old and new cellphone generations. Your operating system will not support for your mobile phones usb driver manually so you will need to download and install usb driver of your phone before connecting your phone with pc. You can use your mobile as a modem for internet and you can manage your phone apps on your pc like sending or receiving messages.
During installation please disconnect your phone from your usb port if your phone was already connected with your pc because your phone will built fact in your installation.
Now you can download latest usb driver of your phone from below links