need help, old laptop to tv as monitor.

so my girlfriend just got a brand new tv to use as a montier for her laptop sence the screen is getting lines through it, she got the wireless keyboard and mouse to go with it, but the tv doesn't have a vga port, so we had to run around and find a vga-dvi and then got a dvi-hdmi so i need to know how the hell does it work. we cannot get the picture to show up on the tv and im fairley good with computers but this is new territor for me, everything is hooked up right but when we go to the settings and try to activate the tv as a second monitor it doesint even dectect it, we did everything the troubleshooter told us to but were stuck. HELP PLEASE.

DVI can be converted to D-Sub (VGA) but not the other way around. The later is an analog output, while the former is digital. I've seen specialized hardware for this stuff, unfortunately they're pretty expensive as in essence you need a full blown analogue-digital converter.

http://www.amazon.com/gp/offer-listing/B001VNL5N6/ref=asc_df_B001VNL5N61333235?ie=UTF8&condition=new&tag=dealtmp130-20&creative=395165&creativeASIN=B001VNL5N6&linkCode=asm

IMHO you're much better off finding a converter from VGA to another analogue input your TV does accept.

http://www.amazon.com/TV-out-VGA-S-Video-Cable-Adapter/dp/B000P3UB24

fucking god damnit. i wish the best buy employed had there heads out of there asses. could have saved uss a shitton of time. but now shes gonna be freaking out cuase the "only" reason she got the tv was to use her laptop for it. wich pisses me off to be honest.

Mine use a VGA port anyways... i seen a vga to hdmi port at best buy monday with is impossable since vga is analog and hdmi is digital, must of been a usb to vga/hdmi.

gotta buy a convert box to do vga to hdmi.
Most hd tv's have hdmi, VGA, rca, S cable and dvi port on them standard.

Anyways can upgrade the graphics card to a newer hdmi port or get the usb to all monitor port converter...

Upvote for Monoprice. Bulk LAN cables for $2-3(total).

It's not impossible to convert the signal. You just have to re-digitalize it.
However that won't improve picture quality et all. So that's why I recommended you're better off using an analogue input on the TV.

Here's another trick: USB to HDMI. This is in fact an external videocard.
http://www.amazon.com/Plugable-Adapter-Multiple-Displays-2048x1152/dp/B0038P1TP4/ref=sr_1_2?ie=UTF8&qid=1290909634&sr=8-2

http://www.amazon.com/Plugable-UGA-125-Multiple-Monitors-1280x1024/dp/B003IE49T8/ref=sr_1_7?ie=UTF8&qid=1290909634&sr=8-7

These will give you true digital output, so picture quality is superior to analogue outputs.

Can't you take back the TV and switch it for another model? The retailer who sold it to you gave imprecise/wrong advice and his warranty must cover limited take-back or switch for a different product. (At least in the EU that is the norm).