Please help. Urgent -- undefined index: #default_value

Hello,

Please help..I am getting undefined index error in the file form.inc. If somehow i get to login page, then I get undefined index: #validated error. I am using drupal 4.7.2. Below is the error message that I received. The error message is coming as soon as I go to the drupal webpage

Any idea how it can solved or are there any patches for it

Regards

======================= ERROR MESSAGE ============================
Source File: C:\Apache2\htdocs\drupal\includes\form.inc Line: 381

Line 376: $function = $form['#type'] . '_value';
Line 377: if (function_exists($function)) {
Line 378: $function($form);
Line 379: }
Line 380: else {
Line 381: $form['#value'] = $form['#default_value'];
Line 382: }
Line 383: }
Line 384: }
Line 385: if (isset($form['#executes_submit_callback'])) {
Line 386: // Count submit and non-submit buttons

Call Stack:

#0 C:\Apache2\htdocs\drupal\includes\form.inc(381): QcodoHandleError()
#1 C:\Apache2\htdocs\drupal\includes\form.inc(431): form_builder()
#2 C:\Apache2\htdocs\drupal\includes\form.inc(115): form_builder()
#3 C:\Apache2\htdocs\drupal\modules\user.module(557): drupal_get_form()
#4 (): user_block()
#5 C:\Apache2\htdocs\drupal\includes\module.inc(185): call_user_func_array()
#6 C:\Apache2\htdocs\drupal\modules\block.module(638): module_invoke()
#7 (): block_list()
#8 C:\Apache2\htdocs\drupal\includes\module.inc(185): call_user_func_array()
#9 C:\Apache2\htdocs\drupal\includes\theme.inc(935): module_invoke()
#10 (): theme_blocks()
#11 C:\Apache2\htdocs\drupal\includes\theme.inc(166): call_user_func_array()
#12 C:\Apache2\htdocs\drupal\themes\engines\phptemplate\phptemplate.engine(160): theme()
#13 (): phptemplate_page()
#14 C:\Apache2\htdocs\drupal\includes\theme.inc(166): call_user_func_array()
#15 C:\Apache2\htdocs\drupal\index.php(29): theme()