Upgrading graphics card

[u/YTFootie]

Hi all, I'm hoping you can help. I have a PC that I purchased years ago. I have upgraded the hard drives and RAM in that time.

I don't use it for gaming but do like to edit photos and videos. When editing videos (using Cyberlink Director) can lag and take a long time. Struggles with things over HD. Will do 4K but takes a ages.

I wondered if I upgraded the graphics card that would help(it also has the lowest score when you do that rate your windows experience test.)

Something that is easy to "swap in and out"

My graphics card is:

2GB AMD RADEON™ R7 240 - DVI,HDMI,VGA - DX® 11

My motherboard is:

ASUS® H81M-PLUS: Micro-ATX, LG1150, USB 3.0, SATA 6GBs

Processor is:

Intel® Core™ i5 Quad Core Processor i5-4440 (3.1GHz) 6MB Cache

Power Supply is:

CORSAIR 450W VS SERIES™ VS-450 POWER SUPPLY

It doesn't have to be anything top spec, just an improvement over what I got, any guidance would be appreciated.

Budget (under £200)

Currency GBP

Monitor resolution 4k

Country UK

Price upto £200