this is what I found on a guilds webpage while ago.......
1. Set the eqgame.exe file in your EQ folder and the EQ icon to 'Run as Administrator' (right-click, Properties, Compatibility tab)
2. While in the Compatibility tab, also check the box that says "Run this program in compatibility for:" And select Windows XP (Service Pack 2) from the drop down box.
3. **MOST IMPORTANTLY** Take off the UAC!! (User Access Control) This is the "Cancel or Allow" window deal that keeps coming up everytime you go to run something. This is found in your Control Panel, User Accounts. You should see an option that says "Turn User Access Control on or off" Turn that POS off.
The reason your "play" button isnt showing up is because the UAC isnt allowing your EQ files to be updated (if you looked at the properties of your EQ folder prior to disabling this you would notice that it is "Read-only" and no matter how many times you told it not to be read only, it wouldnt change).
Once UAC is off, re-run your patcher. If you dont have access to transfer the files from your old computer you will have a few hours of downloads to go through (even with the Platinum Edition). Alas, you should see the Play button once it is done.