Problem Updating Games(SC and GW)

I have a fairly new computer, I got it a couple months. It's been having a problem of sorts. When I try to get the lastest patches for games Starcraft and Guild Wars, I have trouble. The problems are difrent, but I think they might be stemming from the same...what ever is causing the problem.

Starcraft I hadnt played in years, but decided to reinstall it. This is the first time to play it on this computer. When the BlizUpdater runs, it says it is unable to close the game, the same happened on WC3. I've tried restartign the computer and everything else they list to try, and the game is closed. I also tried downloading the patch independantly to install, but had the same problem, even without opening the game since i had restared the computer.

As far as Guild Wars goes, I have to reinstall the game everytime there is an update. The game was fine on my old computer and I had no problems. The message I recieve is after downloading the update, it atempts to connect to the server, but says something like: Acesses is deined to modifying the file. I've checked and my firewall settings are fine to allow it.

I'm really lost. If anyone could help me I'd truely apreciate it!

Anyways, here are my system specs:
Window XP Home SP2
AMD Athlon 64, 2000 MHz (10 x 200) 3200+
MSI RS480M2 (MS-7093) (3 PCI, 1 PCI-E x16, 4 DDR DIMM, Audio, Video, LAN, IEEE-1394)
ATI Radeon Xpress 200, AMD Hammer
640 MB (DDR SDRAM)

If anyone could even shed some light on the problem, I would really be thankful, I tried checking control panel settings and everything, and my account is the only one on the cmputer and as such is the administrator.

If you ened anymore information, I can provide it.
Thank for reading!