disabled admin account black screens my hp laptop

I have recently upgraded from XP to Vista via DVD booting. I have recieved a few errors etc.. to overcome this e.g unistalling windows defender etc.. I have came across the problem of my scrreen going black etc.. now and again although there is HD activity....any advice? Also when i boot up i cannot login using my adim account as it says this has been disabled....why? iam only able to login when i use my username and connect to my Domain in the office.
Any help would be appreciated

I have recently upgraded from XP to Vista via DVD booting. I have recieved a few errors etc.. to overcome this e.g unistalling windows defender etc.. I have came across the problem of my scrreen going black etc.. now and again although there is HD activity....any advice?

I have heard of buggy display drivers causing the screen to go black for a few seconds every now and then. I am not aware of any solutions, other then updating to latest display drivers.

Also when i boot up i cannot login using my adim account as it says this has been disabled....why? iam only able to login when i use my username and connect to my Domain in the office.

The Administrator account is disabled in Windows Vista, except from Safe Mode. Microsoft is pushing the best security practices that other OS's allow and encourage:
- Complete admin access should never be used xcept in emergency - If you need admin access to something, you only give a certain program admin privledges - Unless explicitly ran as admin, all programs run with standard user rights
So, the full admin account is disabled except in safe mode, and members of the Administrators group no longer run with full admin privledges; instead, they have to explicitly run programs with admin privledges by right-clicking them and clicking run as administrator (or the program may ask for admin permission).
If this new security model is unacceptable, you can re-enable the built in administrator and/or disable the User Account Control (UAC is what limits the Administrators group members privlidges) from the User Accounts control panel, although Microsoft highly recommends that you do not do this.
- JB