Lag when entering area

When I enter an area, the game lags badly.
I was able to help the problem somewhat by clearing some hard drive space.
I have a 37gb hard drive, the problem was horrible when i had 35gb used, i deleted a bunch of stuff, and i'm now and 25gb used. The problem isn't as bad as it was, but it is still definately noticable.
After clearing this much space i did a hard drive defrag, and gw.dat was the only file it could not defrag, and it was in 2700+ fragments.
I think defragging this file will speed up GW when I enter a zone. Does anyone know how to force this to defrag, or should i delete gw.dat, defrag again, and then redownload.

Any ideas would help!

Also, i really think the problem is accessing the hard drive more than internet conneciton lag.
thanks

Then why use the term "lag" which usually, by itself, refers to network latency issues?

The defragmentation tool supplied with Windows sucks. If you want to defrag the partition fully you need some 3rd party software like O&O Defrag, which is available as a 30-day trial last I checked. Just download that and leave it running one of its Complete defragmentation options overnight.

Note that freeing up some space on that tiny HDD of yours could prevent further fragmentation, and having less crap on the drive makes the defragmentation process faster, so you might want to delete any unneeded stuff _before_ you run the defragger. Also, if your gw.dat is very old it could have tons of old junk in it, so deleting it before defragging and redownloading it completely with -image afterwards may leave you with a somewhat smaller gw.dat file, which someone with a 37 GB HDD might appreciate.

How much physical RAM does your system have? If Guild Wars needs more RAM than you have available, it starts using virtual memory which caches data on your hard drive. This is normal and even does it to some degree on systems that have 2GB+, but it causes problems on slower systems due to the fact hard drives are extremely slow compared to RAM. Its important to a.) have some space left on your drive and b.) make sure its properly defragmented.

There is a sticky in the Tech area of this forum named 'Bad Lag? Try this.' which has a link to a program for single file defragments.