Not able to log on after patches

I have had this problem for a couple of weeks now. Right after a patch whenever I try to connect to Guild Wars and before the log on screen I get this error message:
"Unable to Install

The installer could not write Guild Wars to the specified
directory. Please check that you have administrative access,
that you have permission to install programs in the specified
directory, and that there is sufficient space availble on the
drive."
Last week when this happened I tried to repair Guild Wars with Add/Remove Program, it didn't work it gave this error when tried to repair. I tried to remove and reinstall Guild Wars but I could not reinstall because it gave the same error. This error cleared up by itself about a day or two after the patch.

Anyone else having this problem?

My computer stats: AMD Athlon XP 2400+CPU, Epox nForce2 motherboard, 1 Gig PC2100 RAM, PowerColor Radeon 9500Pro video, and 80gig 8MB cache Maxtor hard drive.

I do have the correct port open on my firewall.

Sounds like the Registry may have corrupted itself when trying to reinstall Guildwars update or something else you have done in the meantime.
Or possibly something else has gone wrong.

How long was the machine last rebuilt?

Also, are you able to completely remove Guild Wars by the Uninstall option?
If not, then you will have to do one of two things.

Manually uninstall all the files by deleting them and then going through the Registry and removing unnecessary Guild Wars Reg entries(Don't advise this if you don't know what you are doing) or try and find a Reg Cleaning program to do the same thing.
Then try and reinstall Guild Wars and see what happens.

If this fails to work, then you may well have to reinstall Windows to fix the registry, as sometimes when this occurs, the Registry is very hard to repair and Reinstalling windows is probably one of the only safe ways to completely fix it.

I was afraid of that I have been having other issuse with other games not running right. That might be the problem
Its been about 6 months since I built the machine so it is getting time for a rebuild. The hard drive is getting cluttered with unused and removed programs. So I'll rebuild it instead of hacking the Registry that could lead to more serious problems.
After I tried to remove it with add/remove programs I went into Program Files to remove the Guild Wars folder so I could reinstall it clean. It told me that GW.exe could not be deleted because another person or program was using it. I looked in task manager and GW.exe was not listed on the processes tab.

I'll just reload and be done with it. I'll let you now how it works out. Thanks fot you help.

I reload my system last weekend to see if that fixed the problem. And today I was able to log on after the patch downloaded no errors. Thanks for your help Dirkiess.

I just got this today. It would keep downloading patches, when there weren't any, and then give me an error=50. Tried an hour later and it worked. Maybe GW serverside problem?