I've got a garmin E-Trex Vista CX and Mapsource software. After creating routes & waypoints (for Ben Nevis, Scafell Pike & Mount Snowdon) when I download these to the GPS unit each subsequent download deletes the previous one.The latest download is O.K. withcontour lines etc. but the other two just show the route and waypoints (n0 contour lines etc.) Help, going round the twist!!

From the saved data when you backed it up on the computer. Use Garmin Express to transfer.

How to Backup User Data from GPS 72/76 or GPSMAP 76/76S

https://support.garmin.com > en-CA
It is recommended to occasionally back up the user data on your GPS 72/76 or GPSMAP 76/76S. User data includes waypoints, routes, tracks, and geocaches.

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  Transfer User Data From MapSource to a GPS 72/72H/76 or ...

  https://support.garmin.com > en-CA
  To transfer user data, such as waypoints, routes, and tracks from the MapSource program to these devices, some additional equipment will be required.
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  Manually Creating Waypoints on GPS 72/76 or GPSMAP 60 ...

  https://support.garmin.com > en-CA
  Press and hold Enter · Wait for the New Waypoint screen · Release Enter · Highlight the Coordinates field · Press Enter · Adjust the coordinates as desired with the ...
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  Backing Up Userdata (Waypoints, Routes, and Tracks) From a ...

  https://support.garmin.com > en-CA
  Before updating device software, it is recommended that you back up user data like waypoints, routes, and tracks. This should be done at regular intervals ...

You cannot load maps to the unit using the Trip and Waypoint Manager software. That software only does what it's called - it transfers routes and waypoints. To install maps onto your GPS, you will need Mapsource, which normally comes with the maps. Once it's installed on your PC, you hook up your GPS with a mini-USB cable, choose which maps you want transferred to the unit, and then the Mapsource software will knit the map segments together and transfer them over to the unit. Hope this helps.

From browsing the manual (page 20) for your Garmin nüvi 350, it looks like you will be able to do this by creating the route in MapSource, saving it as a GPX file, and then loading it to your nuvi on an SD flash memory card.

The Nuvi 350 doesn't support custom routes. You can create waypoints (or custom POIs) for each location and manually pick waypoints as you travel, but there is no way link all the points together into a route. While you can upload a GPX file to it, it won't contain the route, just waypoints. When you pick a waypoint and tell the 350 to take you there, it's going to calculate the route based on the settings (ie, vehicle type, shortest distance, etc). It won't follow a predetermined route.

There are two ways you can load a way point.

1. Hit mark on your GPS. Push up on your rocker until the coordinates are highlighted. Once they are hit enter. From here you can change the coordinates to what ever you want.

2. If you have the software (Mapsource Trip & Waypoint Manager) you can enter the waypoint by going to "Edit" then "New Waypoint" or hit Ctrl + W as a shortcut. Once you create all the points you need, plug in your GPS and turn it on, then click "Send to Device"

Make sure that your mapsource and GPS are both setup on the same datum and lat/lon style corrdinates as well or it could throw it off.

You can download tracks and waypoints via EasyGPS for free, or ExpertGPS or Garmin Mapsource. These programmes will transfer waypoints, tracks and routes to your PC.
If this solves your situation, please come back and rate our solution. Thankyou.

To enter a waypoint, either use Mapsource software and transfer to the unit, or else create a waypoint and then edit it to the proper co-ordinates.

I have found that waypoints, routes and directions work only when I load it on the unit itself as opposed to the SD card. The SD card works more like an expansion slot for pictures or maps.

When you open up Mapsource you'll see the map on the right and the pane on the left, above the pane there are 4 tabs (Maps, Waypoints, Routes and Tracks). As you select a map or create a waypoint, route or track. It will put a number in parenthesis which will increase in numbers as you add an item corresponding to each category, for example if you create a waypoint. So once you have done that, click on the TRANSFER tab in the Menu selection bar and choose SEND TO DEVICE. A window will pop up that will say...Device: with a drop down menu if your Garmin unit has an SD card in it, if not it will just show the Garmin unit. Then right below that there will be a section that says WHAT TO SEND with 4 check boxes that will say Maps, Waypoints, Routes and Tracks. Make sure that you have selected the Garmin unit, not the SD, and the waypoints, routes or tracks you want to send. I hope this solves your problem or at least points you in the right direction...

and what happens exactly when you try this?

Are you running Vista? If so, contact Garmin for a download that allows the maps to be loaded.

Detailed road map data, with addresses, hotels, gas stations, etc. can be loaded into a data-card/cartridge/memory-card using Garmin's Mapsource software such as Metroguide or City Navigator. This can be changed as needed via a PC.
The 295 does not have driving routing/guidance through the streets as most of today's GPSs have, but it will show you exactly where you are on the street (but it should be switched to Road mode).
Driving routing is possible on the PC using Mapsource, but ithe route doesn't transfer well to the 295 because of the limits on waypoints.