drangon hunter sir-
Please understand that when starting a query in the technical section, please refrain from taking the name of the seller.
Though not necessary while troubleshooting your issue, you may say it was bought recently and a used one from someone on TE (most regular members would know the person anyways).
But without ascertaining the exact nature of the problem at your end and the cause, mentioning name in the very first post is highly undesairable imho.
It may malign his/her reputation or at least cast a shadow of doubt on him/her having sold a faulty product in the minds of others, even if such a doubt may or may not exist at your end.
Coming to the issue at hand,
- As mentioned by many already, ATI 5xxx cards and driver issues with win7 are not uncommon.
Most have found an older version, depsnding on model, to work better than the latest version iirc.
I have heard of grey screen. Can you please post a picture of the violet screen?
- Please check if your motherboard BIOS is up to date too.
- Also do check if the card is seated properly in the slot and the power connectors are properly inserted.
(The card should slot in freely and flush with the back of the case, without having to be pushed to hard.
One may need to loosen the mobo screws and tighten after re-alignment if mobo is too close or too far from the back of the case.
While pushing in the PCIe power connector, it's usually better to grab the bunch of wires that exit the connector instead of the connector itself.)
Can you please post a picture of your case internals with the side panel removed?