Your hard drive may be damaged.
Listen for noise that might sounds louder than usual. Does it sound like a jet engine? Does it click loud when you open an app or move in UO?
Go ahead and pm me the specs.
Do you notice lag in any other programs?
A ram stick could have gone bad. Check your on system specs to make sure its reading all of your ram.
Video card could be bad but it would not likley be the case if you are able to log into uo period.
Do an internet speed test a
www.speakeasy.net and on bottem right click the link for internet speed test. Choose the host closest to your location.
You can also use toast.net. I use both because both show you different things.
On toast.net, select internet speed test from the main page. And you'll see a column with 6-7 option on left side of page.
Try the "text and image" test and the Blue Angles (Large Image file) test. Try different hosts.
The image should load quick (maybe about - 1/4- 1/3- even 1/2 at a time)
It will show you results based on average user tests for each specific one plus the results of the major ISP's in the nation.
The speak easy test runs more like a meter that mesaures your speed as it goes.
If either of these tests seem to be slow to you, then its probably a connection issue.
You can still ping 13 and get packet loss.
Packet loss is a sudden/sharp drop in your connection.
You may run good for 3 secs then stop, 3 secs then stop etc.
If this is happening, every couple tiles you run in UO, you will lag.
Make sure your wiring isn't damaged. Make sure that no connections are rusted outside and that your cables are not damaged. These will cause packet loss yet you still still show 13 ping.
Also make sure that the power outlet your modem is plugged into is not in fact going bad. If you have a ton of shit running off one outlet, or the wiring in the power outlet is going bad, your modem will not function to is maximum effect due to lack of power.
With the info you gave, the above is what I suggest to check.
Try running a different game. Try one that isn't an online game like sim city or something. Try another online game if you have one.
PM or ICQ the specs (37533374).
Ohh yeah, is your antivirus/firewall running? Did you install new/different software? Some antivirus's are resource hogs as they update online from their hosts as well as scan your compute while it runs.
If you reformatted, you shouldnt have spywaye...........which too would cause the lag.
Try the above, pm the specs, let me know what you find. Hope this was helpful.