errr... how handicapped?
First, find out what graphics card you are currently equiped with to ascertain whether its better than the V550. You can just post it on this forum and any no. of us can tell you.
I assume the worst case scenario and assume you are using win 98, atx casing.
1- turn off main power switch - the wall socket
2- take screw driver and unsrew/open the casing, this may be difficult if your casing opens backward in which the wires back there get in the way. Just pull them out but try to remember what goes where.
3- look for that board which is connected to the monitor out. Unplug the monitor plug if you havent already. This is your old graphics board, the one you want to replace.
4- chances are, there is a screw holding down the board. Unscrew and pull straight out, carefully.
5- note the color of the slot it was in, if its black its PCI. If its brown... then it would be interesting to know what the old board was.
5- open and unwrap your spanking V550.
6- insert the V550 into the recently vacated slot.
7- do steps 4 to 1, backwards.
8- boot up, if u have problems good luck.
9- Win 98 will detect your card and may ask you to put in the driver disk. Follow install instructions. If no driver disk, then use default/most appropriate drivers.
10-get online and go to NVidia.com, dl the latest reference drivers - detonator 3.0something.
11-install the detonator drivers and reboot.
u should be set to go. just make sure to re-detect your graphics card with UT ->UT safe mode