Install versus reinstall - lose everything?

Last week, my PC suffered a corrupted driver, lost LAN connectivity, blah, blah, blah. The result was a total boat anchor of a PC (at least as far as getting on the Internet is concerned). I have a new copy of W7 on the way. My intention is to reload the OS, so that the PC performs well again, while retaining the software that's currently on it. Is that doable, or do I have to unload it all to external disks first? BTW, I think WS2_32.DLL took a hike. It's there, but I can't use Malwarebytes on it, without Internet connectivity.

Dell doesn't have any Windows 7 drivers listed for your computer (XPS 410). Therefore, it will be a gamble to load Windows 7 and have the needed Windows drivers for everything . It might work.

There is no direct upgrade available from XP to 7. However, you could try an aftermarket program like PC Mover to upgrade from XP to 7. I've never used it, nor have I used a similar product. Here is a nice write up from someone who used PC Mover to upgrade from XP to 7:
http://www.windowsusers.org/pcmover.html

I suggest that you first get LAN connectivity working, before trying to do the upgrade. If you have an available NIC (Network Interface Card), you could install it in the computer, so that you could get online. Then do a Windows update, to see if it finds a driver for the internal NIC. If it does, then install only that one update. Then power down, remove the NIC that you installed, plug the Ethernet cable into the internal NIC, and power up, to see if the internal NIC now works. This method has never failed to work for me.

Any of these NICs should work in your computer:
https://www.amazon.com/s/ref=nb_sb_ss_i_6_13?url=search-alias%3Daps&field-keywords=ethernet+card+pci+express&sprefix=ethernet+card%2Caps%2C234&crid=13J2WU04ER28F

Or, you could try an external USB NIC:
https://www.amazon.com/s/ref=nb_sb_s...=1RTWVIMKV9ND5

Make sure that whatever you buy will work with XP.

My PC was already on 7 (courtesy of my dad, when he owned it). This is just W7 (non-working) to 7 (new).

Then I suggest you use the method I described above to get your NIC working. Once you have gotten your NIC working, it will be a lot easier to get any other problems resolved.

Make sure you do a backup now, and also after you get something working.

The copy I bought was off ebay, and was still sealed.

If you just having trouble with for the internal NIC, open device manager, right click on the the network adapter and uninstall it.
Then On Action tab - Scan for hardware changes.

Don't understand why did you buy another copy of Win 7 if you already have one. Don't you have the copy your dad used on the computer?

No, I don't have the original copy that was installed. I guess it came preloaded with XP, and then 7 was downloaded, it subsequently failed and was repaired with a volume license version of W7, I guess.

On the the current version of Win 7 run MS diagnostic https://go.microsoft.com/fwlink/?linkid=52012
It will tell witch version (OEM, Retail or OEM slp) is installed. If it is a OEM or retail you can retrieve the key and use any Win 7 disk to install. If you don't have a disk you can download it.
http://www.klinzmann.name/licensecrawler.htm

There are two options to install win 7
1) My favorite is Clean install Clean Install Windows 7 - Windows 7 Help Forums as it start from scratch and get rid of all trash.
- Backup your data
- Clean install Win 7
- Install all drivers.
- Install the updates. Use the offline SP2 and security only updates. MS releases SP2 for Windows 7 - Windows 7 Help Forums
- Reinstall all programs.
- Restore your data.

2) Repair install. It will reinstall windows and keep your programs, data and all trash. Repair Install - Windows 7 Help Forums
- Backup your data
- Install the updates. Use the offline SP2 and security only updates. MS releases SP2 for Windows 7 - Windows 7 Help Forums

Do you have any restore points pre-dating the time your issue began? If you do it could save you a lot of time and trouble. Run as administrator 'rstrui.exe'.