PC freezing and browser shut-downs

I am using a back-up notebook PC (Dell M1330 with Windows Home Vista, stock 320GB 5400RPM HD) while waiting for my replacement HD to replace the failed HD in my usual PC. In the past 2 days, I have been encountering two problems that are rapidly becoming hindrances to using the PC. The first and more serious problem is when I am viewing videos with either Windows Media Player or VideoLAN media player, the player and entire PC freeze about 15-30 minutes after the video starts. When this occurs, I cannot restart the video or even close the video and media player. Moreover, the PC as a whole freezes--I cannot open or close any windows, open any other programs, close the errant player or any other windows with Windows Task Manager, or even activate the shut-down or restart sequence from the "start" key. I have to resort to a crude and cold shutdown of my PC using the power button and powering the PC back on again. The second problem is when browsing the internet and I click on a URL that opens another window and then attempt to close that window, I receive an error message stating Internet Explorer (IE) has stopped working and both the original and secondary windows close, and often a new IE window opens.

I use Microsoft Security Essentials for anti-virus and Malwarebytes for malware protection; both are up-to-date, I ran full scans with both and have not detected any viruses or malware. I used the add-ons manager in internet options to disable any add-ons that were not necessary or part of any program I used, but this did not rectify the problems. Any suggestions for correcting these hang-ups, especially the first one with the videos?

Thanks for reading and any help.

 

For the first one, it sounds like a video card issue. Have you installed the latest up-to-date drivers for it?

For the second problem, I'd have no idea... Is it only with Internet Explorer?

 

I appreciate the (solitary) response to my post (thanks joelkrause57). I have since been able to correct the problem with a rather simple solution I probably should have thought of before initially posting the situation. Both problems--the Internet Explorer (IE) windows not closing properly and the Windows Media Player and VideoLAN media players stopping and freezing both themselves and the PC--were corrected when I upgraded my IE 7 to IE 8. I had avoided upgrading my IE to version 8 for many months because I preferred the IE 7 handling of the Favorites bookmarks to IE 8. When I upgraded to IE 8 earlier today, I realized that its Favorites bookmarks were actually not significantly different from IE 7, contrary to my earlier erroneous impression. I upgraded to IE 8 surmising that IE 7 had been corrupted or perhaps was not compatible with one or more of the Windows Vista updates. Why the IE problems would affect operation of both Windows Media Player and VideoLAN media player remains unknown to me; I can only surmise that some aspects of IE interact with the media players, perhaps their windows aspects.