I'm just starting to troubleshoot an issue but I've noticed my C: drive is filling up over night. It's literally filling up 70GB of data that is cleared out upon reboot. I assume something is causing the OS to write HUGE amounts of temp files for some reason.

Check system properties advanced how much space is alloted for the page file.Seesons greetings!

Been there done that,,,,, there is no reason the default install should behave like this,,,PageFile was only 8058mb,,, I'm planning to run WinDirStat next time I see this issue crop up. For example, right now,,, 40GB free on a 75BG drive,,, within 48 hours it will be less that 900mb free,,,,

Ok, examine your processes in task manager see what's using mem and cpu.Seesons greetings!

Does the issue begin to occur as soon as Windows 7 installs on your hard drive? At this point, it is necessary for you to run the Anti-virus programs to ensure that your computer is clean. Then, lets run Check Disk Utility to check if there is error codes on your hard drive. Method 1: 1. Click the Start Button, type "cmd" =>Right click on it and choose Run as Administrator=>Input the following command and press Enter Key after it. Chkdsk /f /r 2. Please type Y and press Enter. 3. Please restart the computer and let the tool check all drives on the computer. Method 2: 1. Click the Start Button=> Computer=> Right-click on the problematic hard drive and choose Properties. 2. Switch to the Tool tab and click on the "Check Now" button. Click Continue if necessary. 3. Select both the "Automatically fix file system errors" and "Scan for and attempt recovery of bad sectors" options. 4. Click Start. Note: It is recommended to repeat the steps above to check the disk twice so that most of the error can be found and fixed. Also, lets run Disk Cleanup, Disk Defragmenter and Check Virtual Memory as well. If your computer is clean and no error code was received after running Check Disk Utility, you can try temporarily disabling System Restore to check if the issue persists. Also, lets try adjust the amount of space used by Volume Shadow Copy. Adjust the amount of space used by Volume Shadow Copy ================================================ 1. Run CMD as Administrator. 2. Click Continue when the User Account Control window appears. 3. Type the following command and press Enter: Vssadmin resize shadowstorage /on=C: /For=C: /MaxSize=75GB (This number is just an example. Use as much as you want, the maximum number of the MaxSize is 15% of the partition space). In addition, since I am not sure if WinDirStat can work properly on your computer, I recommend downloading and installing TreeSize Free to observe where the precious space has gone to. Hope it helps.

I had the same issue with my computer (Win7). Turns out I included "C:\" to my Indexing Locations and my hard drive was filling up overnight. I excluded my hard drive from the indexing location, now my computer is fast again and hard drive not filling up. Took a while to figure this out, wish someone would mention this in a forum.

Updates take up a good deal of space. Windows installs 30 updates in one shot after a fresh install.

My bad for not getting back to everyone on this,,, About 2 weeks after posting, I resolved the issue. Turned out to be the driver for my tuner card; it was recording all my TV viewing but never cleaning up after itself. Updated the driver, it's all good. I'm running Win7 Ultimate with a Hauppauge WinTV HVR-1250 tuner card.