Xbox Live Achievements not syncing anymore using Windows XP x64

I am not able to unlock an achievement this week from the live.xbox.com profile? Usually, I have earned achievements for over a year now and they were all displaying on my live.xbox.com profile untill last week or so. In this week I earned 10 + achievements and also received achievement notifications and they all showed up unlocked in the game client but the problem is that it didnt update on my profile page? So I think that this issue was caused by an update to Windows XP, how should i earn it back, please help.

I have also encountered similar problem but that was in the last year. Everything that I knew or read pointed to the problem with my ISP or the router, but my friend has the same router and he didnt face similar kind of issues. So, after doing so research, I uninstalled the GFWL client and installed the 3.0 version of it and ran a game called Tinker offline. After that I just updated my client and I saw that the achievement was now unlocked. Hope that helps you.

I think due to the fact that since you are not playing with a gamertag, your achievements aren't going to transfer. You need to be playing with a gamertag and only then the achievements that you have "achieved" will be saved and synced. So basically, if you don't have a gamertag how did you earn achievements? To earn achievements you must have a gamertag (profile) whether on or offline. If you turn your account into a LIVE one it will sync and you keep the achievements.

I also faced similar problems and finally after hours of searching I fixed it. Here's what i did to to get achievements unlocked on XP64 I've taken to the following:

1. You first need to sign into GFWL using the latest client to make sure your local profile is synchronized on your Xbox 360.
2. Exit GFWL.
3. UNINSTALL GFWL -- both the Client and the Runtime.
4. INSTALL the GFWL 3.0 client.
5. Play game (in this case, Tinker). Use your "GregLeg" profile, but DECLINE the upgrade when prompted.
6. If you unlock any achievements during the session, sign in, and this time ACCEPT the update when prompted. Now the achievements will be synced to your Live account.

Hope that helps.