System access problems

[Mrsash]

I dont know where to post this problem. I installed something recently but suddenly I dont have access to task manager, system restore, registry etc. I know its dumb but guess messed up. It says contact your admin to get access but am from the admin group. It says access has been turned off in the group policy.
thanks

Winxp SP1+RU1

[isogonic]

since the problem started after installing a app, and you didnt say what it was, the first thing that comes to my mind is malware.
update and run any av you have. run or install a malware removing app, like lava softs ad aware or spybot search and destroy.

[Mrsash]

it looks like its stuffed. I have scanned with norton, adaware, spy sweeper but cant get it to work. It has even left no access to cmd. I guess I need to format. Now I need to figure out what I have to Backup. Do you guys know where are the files for firefox, since I not only want o backup bookmarks but other settings and history as well.
God I have to make up a list of what I need Backed up. Do you guys make a List or just transfer files to CD, DVD's etc?
Oh by the way the tool was a rapidshare hack that I installed. Yes I did not wanna mention it as it was embarrasing. I have finally learnt my lesson.
thanks

[isogonic]

try running ad aware and the rest in safe mode. you can get to safe mode by tapping the f8 key during a computer reboot. another you might try (good for trojans) is ewido anti malware, install update and run it in safe mode also.